Comcare v Reardon

1. The appeal be dismissed with costs. Note: Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011 (Cth).

IN THE FEDERAL COURT OF AUSTRALIA TASMANIA DISTRICT REGISTRY GENERAL DIVISION TAD 17 of 2015

JUDGE: MORTIMER J DATE: 4 November 2015 PLACE: MELBOURNE (via video-link TO HOBART)

REASONS FOR JUDGMENT 1 The applicant, Comcare, appeals from a decision of the Administrative Appeals Tribunal dated 26 May 2015. By that decision, the Tribunal set aside the applicant's decision denying liability to the respondent under s 14 of the Safety, Rehabilitation and Compensation Act 1988 (Cth) (SRC Act) and found the applicant was liable on the basis that the respondent's employment had contributed, to a significant degree, to an aggravation of her hyperacusis. 2 For the reasons set out below, Comcare's appeal must be dismissed.

Background 3 Mrs Reardon suffers from partial hearing loss, tinnitus and hyperacusis. The Tribunal found hyperacusis is a recognised medical condition characterised by a reduction in normal tolerance to everyday sound. On the evidence the medical experts agreed, and the Tribunal found, Mrs Reardon's hyperacusis caused her to have headaches and pain. Mrs Reardon, who at the time had no legal representation, had contended before the Tribunal that each of these conditions had been caused by her employment in a call centre, in particular the headsets she used and the level of workplace noise including frequent "call bells". Although the Tribunal did not accept that contention, it did accept that her hyperacusis had been aggravated by her employment to a significant degree. 4 As the Tribunal noted in the introduction to its reasons, Mrs Reardon has been a full-time employee of the Commonwealth Department of Health and Human Services since 1988. Her duties from approximately January 2011 involved taking customer telephone calls as a Customer Service Officer in the Paid Parental Leave Team. 5 The Tribunal's factual findings on the sequence of events leading to Mrs Reardon's review application were not contentious on the appeal, and were as follows: 2. By early 2012, Mrs Reardon was experiencing problems with phone headsets she used to do her work. She developed pressure, discomfort and later pain in her head at work, which she initially attributed to the headsets and also to workplace noise. 3. By early 2013 Mrs Reardon was having frequent problems with her headsets, pain in her head and headaches. She initially consulted with her GP on 14 January 2013 and later formally notified her employer by incident report. 4. On 13 May 2013 a claim for compensation was made to the Respondent. Compensation was claimed for injury identified as "Hyperacusis related to workplace noise exposure, with sensorineural hearing loss and tinnitus" ("the ailments"). The claim was refused on 22 July 2013. Subsequent reconsideration confirmed refusal of the claim. (Footnotes omitted.) 6 On 25 November 2013, Mrs Reardon lodged an application for the Tribunal to review that decision. Comcare accepted before the Tribunal that the respondent Mrs Reardon suffered sensorineural hearing loss, tinnitus and hyperacusis, and that those conditions were each an "ailment suffered by an employee" for the purpose of s 5B(1)(a) of the SRC Act. However it disputed that Mrs Reardon's employment had either contributed to or aggravated any of her ailments to a significant degree.

THE TRIBUNAL PROCEEDINGS 7 The Tribunal had before it evidence from a range of sources. Mrs Reardon and two of her supervisors Ms Linda Free and Ms Penny Johnstone gave evidence, as did Mr Nick Bell, the senior rehabilitation case manager within the Department. Each witness was cross-examined. The Tribunal accepted Mrs Reardon as an honest and credible witness. The Tribunal also received signed statements from six of Mrs Reardon's co-workers regarding the call bells that were used. These co-workers did not attend to give evidence and Comcare did not seek to challenge the content of their statements by putting that material to Ms Free and Ms Johnstone. The Tribunal also had access to contemporaneous records prepared by the Department as well as medical expert evidence. The nature and effect of the expert evidence was in issue in the questions of law raised in the s 44 appeal. 8 It should be noted at this point that Mrs Reardon relied on the "disease" limb of the definition of "injury" in the SRC Act. As I set out below, that is why she needed to establish a causal link of some kind between the events she identified as having arisen in the course of her employment and her injury. She did not contend that she had suffered an "injury" in the sense of an "injury simpliciter" under s 5A(1)(b) or (c) of the SRC Act. 9 Although the Tribunal considered that at any given time the workplace noise levels were probably around 80 decibels and at times could well have exceeded that level, the Tribunal held (at [41]) "in the absence of specific reliable evidence about the ambient noise levels, I cannot reach any firm conclusion about the decibel range for noises to which Mrs Reardon was exposed at work." Noting both medical experts had given evidence that typically exposure to noise levels of 70 decibels or less for eight hours would not cause hearing loss, the Tribunal held it could not be satisfied that workplace noise was a significant contributing factor to Mrs Reardon's hearing loss, nor to her tinnitus (the Tribunal considering tinnitus, on the evidence, to be a consequence of hearing loss). 10 The medical evidence before the Tribunal was not uniform on the question whether Mrs Reardon's employment contributed to her hyperacusis to a "significant degree". Two medical experts appeared before the Tribunal to give evidence. Mr Warwick Brennan, an ear, nose and throat surgeon, was requested by Comcare to provide a medicolegal report in respect of Mrs Reardon. Dr Peter Sharman, an occupational physician treating Mrs Reardon, was requested by her to prepare a medical report in relation to her condition and to comment on the opinion of Mr Brennan. Mr Brennan reviewed Dr Sharman's report and provided a further statement at Comcare's request. 11 Although Dr Sharman attributed Mrs Reardon's hyperacusis to the workplace noise, the Tribunal did not accept that attribution, noting Dr Sharman had agreed that Mrs Reardon's hyperacusis appeared to be of gradual onset and not directly attributable to any of the known causes for hyperacusis (hearing loss, head injury, whiplash, acoustic trauma, adverse reaction to drugs or chronic ear infection). Mr Brennan suggested the hyperacusis was related to an undiagnosed ear condition, but without, the Tribunal noted, identifying what the condition was or providing plausible evidence that Mrs Reardon suffered any such condition. 12 Given the state of the medical evidence, the Tribunal considered it more likely than not that Mrs Reardon's hyperacusis was a consequence of her hearing loss and tinnitus. As her employment had not contributed to either of those conditions, the Tribunal did not accept Mrs Reardon's employment had contributed to a significant degree to her hyperacusis. 13 The Tribunal then turned to consider whether Mrs Reardon's employment had aggravated any of her three conditions to a significant degree. The Tribunal accepted Mrs Reardon's evidence that her symptoms deteriorated when using headsets at work and when exposed to call bells and other workplace noises, noting the corroboration of her complaints by contemporaneous workplace records. It accepted that the use of headsets and workplace noises, particularly the call bells, caused Mrs Reardon pressure and discomfort from at least 2012, which later developed into pain and headaches during work hours throughout late 2012 and into 2013. It also found that by January 2013 Mrs Reardon's symptoms had deteriorated to the point that she sought medical advice and treatment, at which point Mrs Reardon was diagnosed with hearing loss, tinnitus and hyperacusis. The Tribunal said (at [53]): Further, I am satisfied that by January 2013, Mrs Reardon's symptoms had deteriorated to the point that she sought medical treatment, and after investigation was found to be suffering hearing loss, tinnitus and hyperacusis. While I cannot be satisfied that employment caused these conditions to a significant degree, I am satisfied that it aggravated the hyperacusis because it worsened her symptoms of pressure, discomfort and headache and made her more sensitive to normal sounds. Employment was a significant contributor to the aggravation for the following reasons: (c) Both medical experts accept that the workplace noises were capable of making the condition of hyperacusis worse; (d) Dr Brennan's evidence that there was nothing in Mrs Reardon's past history of noise exposure outside of the workplace likely to explain her hearing loss, tinnitus or hyperacusis; (e) The absence of evidence of any diagnosed medical condition of the inner ear capable of explaining the conditions; (f) Dr Brennan's evidence that hyperacusis can be triggered by prolonged exposure to unpleasant noise and the call bell was certainly that to Mrs Reardon; (g) The evidence of both medical experts that the hyperacusis is worsened by workplace noise and is causative of incapacity, whereas the hearing loss and tinnitus are not. (h) Dr Brennan's evidence that Mrs Reardon will have difficulty, which I take him to include symptoms and incapacity given the overall context of his evidence, from noise of a warning alarm and use of headsets with prolonged conversation in significant ambient noise, which was a reference to the workplace. (i) That prior to 2011, when the call bells were not operational, and before the use of headsets caused pressure, Mrs Reardon did not have any hypersensitivity to noises, including those outside of work. (j) That the hyperacusis only developed after Mrs Reardon had been repeatedly experiencing difficulty with the headsets and call bells. (Footnotes omitted.) 14 Further, the Tribunal found (at [54]-[56]): The matters included in section 5B(2) of the Act have been considered when giving the reasons above. The authority of Australian Postal Corporation v Bessey has been considered and I am satisfied on the evidence that the worsening of Mrs Reardon's symptoms by employment factors was not transitory, but rather continued indefinitely. Although in his report of 7 July 2014, Dr Brennan describes the aggravation by work to be one of a "minor degree", I do not consider that is an accurate reflection of the effect of the workplace factors that have contributed including the headsets, the call bells and the customer calls. I am required to determine the question of whether employment was a significant contributor to the aggravation. I am not bound to accept Dr Brennan's categorisation of "minor" and do not, taking into account all other evidence received. Factors other than employment may have also contributed to the aggravation of Mrs Reardon's hyperacusis. This does not mean her application ought to fail, as the characteristics of employment do not have to be the sole or major cause of the aggravation. It is sufficient if the employment characteristics contributed "to a significant degree". (Emphasis added; citations omitted.) 15 For reasons which become apparent below, the emphasised parts formed part of the basis for Comcare's challenge to the Tribunal's decision in this proceeding.

Relevant legislative framework 16 Section 14(1) of the SRC Act provides: Compensation for injuries (1) Subject to this Part, Comcare is liable to pay compensation in accordance with this Act in respect of an injury suffered by an employee if the injury results in death, incapacity for work, or impairment. (2) Compensation is not payable in respect of an injury that is intentionally self-inflicted. (3) Compensation is not payable in respect of an injury that is caused by the serious and wilful misconduct of the employee but is not intentionally self-inflicted, unless the injury results in death, or serious and permanent impairment. 17 Section 5A(1) of the Act defines "injury" as follows: Definition of injury (1) In this Act: injury means: (a) a disease suffered by an employee; or (b) an injury (other than a disease) suffered by an employee, that is a physical or mental injury arising out of, or in the course of, the employee's employment; or (c) an aggravation of a physical or mental injury (other than a disease) suffered by an employee (whether or not that injury arose out of, or in the course of, the employee's employment), that is an aggravation that arose out of, or in the course of, that employment; but does not include a disease, injury or aggravation suffered as a result of reasonable administrative action taken in a reasonable manner in respect of the employee's employment. 18 Section 5B of the Act then sets out the following definition of "disease": Definition of disease (1) In this Act: disease means: (a) an ailment suffered by an employee; or (b) an aggravation of such an ailment; that was contributed to, to a significant degree, by the employee's employment by the Commonwealth or a licensee. (2) In determining whether an ailment or aggravation was contributed to, to a significant degree, by an employee's employment by the Commonwealth or a licensee, the following matters may be taken into account: (a) the duration of the employment; (b) the nature of, and particular tasks involved in, the employment; (c) any predisposition of the employee to the ailment or aggravation; (d) any activities of the employee not related to the employment; (e) any other matters affecting the employee's health. This subsection does not limit the matters that may be taken into account. (3) In this Act: significant degree means a degree that is substantially more than material. 19 The history and proper construction of these provisions, in particular the construction of "injury" as it is used in the SRC Act in contradistinction to "disease" has been fully articulated by the Full Court in May v Military Rehabilitation and Compensation Commission [2015] FCAFC 93; 322 ALR 330 at [22]-[119]. The role of the "disease" aspect of the statutory concept of injury is set out at [115] by reference to the judgment of Gleeson CJ and Kirby J in Kennedy Cleaning Services Pty Ltd v Petkoska [2000] HCA 45; 200 CLR 286. At [118] the Full Court said: The meaning of the word "injury" in s 4(1) comes in part from the statutory legal context of, and what is revealed by, cases such as Hume Steel, McIntosh, Zickar and Kennedy Cleaning. The phrases used in those cases are not substitute definitions, but are exemplifications of meaning. Their utility and relevance will often be influenced or dictated by the precise context. For instance, suddenness is of particular relevance when distinguishing between the natural progression of a disease and an event or incident that is an injury. Also, there is a degree of ordinary meaning or common understanding involved, as was recognised by Latham CJ in Hume Steel: the difference between getting hurt and becoming sick. Medical evidence or opinion will, of course, be relevant; but it may not be determinative. The place of common-sense lay inference from a clear sequence of events is to be recognised, as long as any such inference is not denied by medical science. In any particular case there may be a consideration of whether there is a harmful effect on the body, a disturbance of the normal physiological state producing physical incapacity, a sudden or identifiable or distinct physiological change, whether there is an event or incident or clinical diagnosis to explain such change, and such considerations will be made against a background of a distinction in the common use of language between getting hurt and becoming sick. The circumstances and the facts will influence what weight such considerations are given in the drawing of a factual conclusion in any particular case.

Issues raised in this appeal 20 The applicant challenges the Tribunal's conclusion that Mrs Reardon suffered an "aggravation" of hyperacusis that was contributed to by her employment to a significant degree. In its notice of appeal, Comcare identified six questions of law: 1. Did the Tribunal correctly identify the relevant legal test for determining whether the Respondent suffered an aggravation of her condition of hyperacusis within the meaning of ss 5B and 4(1) of the Safety, Rehabilitation and Compensation Act 1988 ('the SRC Act')? 2. Did the Tribunal correctly apply a correctly identified legal test in determining that the Respondent suffered an aggravation of her condition of hyperacusis within the meaning of ss 5B and 4(1) of the SRC Act? 3. Did the Tribunal take into account irrelevant considerations? 4. Did the Tribunal make findings of fact that were not supported by any probative evidence and/or make inferences that were not reasonably open on the evidence? 5. Did the Tribunal fail to address a submission of substance, or a submission worthy of consideration, made by the Applicant on the question of whether the Applicant suffered an aggravation of hyperacusis 6. Did the Tribunal fail to provide reasons, or adequate reasons for its decision in breach of s 43(2B) of the Administrative Appeals Tribunal Act 1975. 21 The six grounds in support of the questions relied upon by Comcare were: 1. The Tribunal identified an incorrect legal test for determining whether there was an aggravation when it stated "A worsening or increase in symptoms of a non-work caused condition may constitute an "aggravation injury" for the purposes of the Act and it is unnecessary for a worsening of the pathology to be present" without acknowledging the important qualification that 'it does not follow in every case that a worker with a pre-existing injury, who carries out work and as a result suffers pain, will have suffered an aggravation of his [or her] injury' (Commonwealth v Beattie (1981) 53 FLR 191 at 201). 2. The Tribunal did not apply the correct legal test when determining that the Respondent suffered an aggravation of hyperacusis in that it did not engage in the question of whether the symptoms experienced at work were merely a manifestation of her non-work related hyperacusis in a work setting and not a worsening of the condition contributed to by her employment. 3. In finding that the contribution of employment to any aggravation of the hyperacusis was 'significant' the Tribunal erroneously took into account matters relating to the onset of the conditions which were irrelevant to the aggravation of hyperacusis. 4. The Tribunal's findings that: 4.1. the Respondent's employment made her 'more sensitive to normal sounds' 4.2. the symptoms of head pressure, discomfort and headache were symptoms of hyperacusis 4.3. the worsening of the Respondent's symptoms by employment factors was not transitory, but rather continued indefinitely 4.4. employment was a significant contributor to the aggravation 4.5. Mr Brennan accepted that the workplace noises were capable of making the condition of hyperacusis worse were not supported by any probative evidence or involved inferences that was not reasonably open on the evidence. 5. The Tribunal did not address the Applicant's submission that work was merely the setting in which the Respondent experienced symptoms of hyperacusis and employment did not aggravate the condition of hyperacusis. 6. The Tribunal ignored evidence that was relevant and potentially significant without explaining why it did not accept evidence that was central to the Applicant's case. 22 Comcare's written submissions identified the following issues for resolution: Comcare challenges the Tribunal's conclusion that Ms Reardon suffered an 'aggravation' of hyperacusis that was contributed to by her employment to a significant degree. The issues for resolution in this regard are: (a) whether the Tribunal misconstrued, and/or misapplied, the relevant legal test for determining whether Ms Reardon suffered an 'aggravation' of hyperacusis within the meaning of ss5B and 4(1) of the SRC Act; (b) whether the Tribunal took into account irrelevant considerations; (c) whether the Tribunal made findings of fact that were not supported by any probative evidence and/or made inferences that were not reasonably open on the evidence; (d) whether the Tribunal failed to address a submission of substance or a submission worthy of consideration made by Comcare; (e) whether the Tribunal failed to provide reasons, or adequate reasons, in breach of s43(2B) of the Administrative Appeals Tribunal Act 1975 (Cth) (the AAT Act). (Footnotes omitted.)

Consideration 23 I commence with some general observations. Mrs Reardon was, as I have noted, self-represented before the Tribunal. Her partner, Mr Reardon, assisted her and indeed conducted some of the cross-examination on her behalf before the Tribunal. It is apparent he did so diligently and with considerable care. However, he is not a lawyer and therefore, if there were gaps in the cross-examination of some witnesses (especially, for example, Mr Brennan) I consider that to be an explanation. I do not consider any gaps tell against the lawfulness of the Tribunal's decision. 24 There appeared to be a general criticism of the Tribunal by Comcare in its oral submissions on the appeal, contending that it was legally erroneous for the Tribunal to find (as it did) that neither Mrs Reardon's hearing loss nor her tinnitus was aggravated by the employment, only the hyperacusis, especially where the Tribunal had found her employment did not cause or contribute to any of the three ailments themselves. In my opinion there is no necessary inconsistency in the Tribunal's findings. On appeal, Comcare accepted that Mrs Reardon suffered from three compensable conditions under the SRC Act: sensorineural hearing loss (bilateral), hyperacusis (bilateral) and tinnitus (bilateral). Therefore, the Tribunal's task on review was to determine whether it was satisfied on the material before it that Mrs Reardon's employment either contributed to a significant degree to the onset of any or all of those conditions; or that Mrs Reardon's employment aggravated any or all of those conditions. 25 It is apparent from the Tribunal's reasons that it was satisfied that Mrs Reardon's tinnitus was a consequence of hearing loss (at [44]) and her hyperacusis was a consequence of both hearing loss and tinnitus (at [47]). Contrary to Comcare's submissions, I see no apparent legal error in the Tribunal ultimately making a finding favourable to Mrs Reardon only on the aggravation of her hyperacusis by her employment, when one considers the nature of hyperacusis (a medical condition that concerns a reduction of usual tolerance to everyday sounds) and the nature of Mrs Reardon's work (taking customer phone calls all day using headsets, in a workplace where there were "call bells", other employees talking while they were taking calls, radios and various alarms from time to time). It was a matter for the Tribunal whether it was so satisfied, but as a general answer to Comcare's assertions that there was some obvious legal and logical flaw in the Tribunal making a limited favourable finding of this nature, I can see no such legal or logical flaw. 26 Both parties placed considerable reliance on the decision of Gyles J in Australian Postal Corporation v Bessey [2001] FCA 266; 32 AAR 508. I refer to Bessey below. However in my opinion it is important to exercise some caution in applying what was said by Gyles J, not because of any issues of principle but because his Honour was dealing in that case with the condition of spondylosis, a degenerative condition of the spine. At [12] Gyles J described the Tribunal's error in the way it approached the question of aggravation: From my consideration of [11], [39], and [40] of the reasons, I conclude that the Tribunal acted on the view that the pain suffered by the respondent whilst riding the bike was an aggravation and, as that pain was incapacitating, there was therefore an entitlement to continuing compensation. This was an error of law. 27 The other extracts on which the parties both rely (between [6] and [10]) make it clear that in Bessey there was no evidence of any clinical change to Mr Bessey's spondylosis apparent in the investigations undertaken by the relevant medical practitioners. As Gyles J noted at [12], the Tribunal's decision on aggravation appeared to be based on the pain Mr Bessey suffered while riding a motorcycle in the course of his employment. In contrast, spondylosis was a condition whose worsening was clinically visible through x-rays. 28 In the present appeal, there is no suggestion in the material before the Tribunal that Mrs Reardon's conditions, and any worsening or degeneration, were measurable in this way. More critically, the Tribunal's reasoning process makes it clear that it was satisfied that although it was the tinnitus that caused the hyperacusis (rather than Mrs Reardon's working conditions), Mrs Reardon was asymptomatic until she began having to use headsets at work, and experiencing the other noise-related conditions at work. This, the Tribunal found, to use Gyles J's paraphrase in Bessey, made her hyperacusis worse. Accordingly, the factual contention which underlies many of Comcare's questions of law in this appeal - namely, that Mrs Reardon only suffered temporary pain at work because of the headsets and other factors while her underlying condition of hyperacusis remained at the same level of severity - was not one which the Tribunal had accepted. 29 In different ways, each of the questions of law involves this factual contention by Comcare. 30 Comcare also placed considerable reliance on the decision of the Full Court in Commonwealth v Beattie [1981] FCA 88; 35 ALR 369. While it accepted that Beattie was authority for the proposition that pain brought on by work can constitute an "aggravation" of a pre-existing injury, it submitted that the qualification expressed by the Full Court in Beattie was directly applicable to Mrs Reardon's circumstances. That qualification is contained in the following passage (at 378): It does not follow in every case that a worker with a pre-existing injury, who carries out work and as a result suffers pain, will have suffered an aggravation of his [or her] injury. A worker whose fractured leg is encased in plaster will be unable to put it to the ground without suffering pain and other disability. But that is not a case of aggravation. In such a case any incapacity for work arises only by reason of the pre-existing injury. 31 Comcare made the repeated submission, in relation to each question of law it raised, that what occurred in 2011-2013 to Mrs Reardon at work was analogous to a worker walking on a fractured leg at work, and was not compensable because the pain and other symptoms experienced by Mrs Reardon arose only by reason of her previous, non-work-related incapacity. In general terms, I find this submission unpersuasive. I am confirmed in that view by the analysis of Finkelstein J in Tippett v Australian Postal Corporation [1998] FCA 335; 27 AAR 40 at 43-44. Where the "experience" of an injury (including a disease) is increased or intensified, or recurs, there may be an aggravation. The experience of the injury, or the symptoms, are part of the injury. This includes pain. Finkelstein J then made the following observations about the qualification in Beattie: This passage draws a very important and perhaps obvious distinction between the case of a worker who has a pre-existing injury that causes the worker to suffer pain whether or not the worker is at work and the case of a worker who has a pre-existing injury and it is the activities at work that cause the worker to suffer pain or to suffer pain more intensely. It is only in the latter case that it can be said that the worker has suffered an aggravation of his or her pre-existing injury. 32 I respectfully agree with Finkelstein J. On the material before it, the Tribunal concluded the latter case was Mrs Reardon's situation, and that conclusion was open to it. 33 Comcare also made a general contention that the Tribunal did not grapple with case it put - namely, that what happened to Mrs Reardon at work over 2011-2013 was the gradual progression of an existing disease. As will become apparent, I consider there was no legal error in the Tribunal's approach, it did grapple with Comcare's contentions and the challenges on this appeal quarrel with the Tribunal's fact-finding in a way which impugns the merits rather than the lawfulness of the Tribunal's decision.

Questions 1 and 2: the legal test for "aggravation" 34 These two questions concern whether the Tribunal identified the correct legal test, and second, whether even if it did so, it applied the test correctly. Comcare's submission, relying on Ogden Industries Pty Ltd v Lucas [1967] HCA 30; 116 CLR 537 at 593 and Beattie at 378, is that "aggravation" connotes an ailment which has been "made worse" and has not simply "become worse". In other words, Comcare submits that an underlying disease running its course will not be an "aggravation" within the meaning of s 5B of the SRC Act. 35 The respondent's submissions did not cavil with the proposition as put by Comcare and as enunciated in the authorities. The respondent was correct to accept the distinction between a condition "becoming" worse and being "made" worse by employment as critical for the purposes of s 5B. 36 Under the heading "applicable legal principles", the Tribunal set out at [34] to [37] its understanding of the degree of contribution made by a worker's employment before the injury will be compensable: Whether Mrs Reardon's conditions were significantly contributed to by employment or whether they were aggravated significantly by employment, requires consideration of what is meant by "contribution to a significant degree". This has been settled in law and it requires the contribution by employment to be substantially more than "material". In Su v Comcare the requirement of contribution to a significant degree was expressed as follows, when approving of Justice Finn's approach to interpretation in Comcare v Sahu-Kahn: "When determining whether any contribution of the employment is of 'a significant degree', matters that may be taken into account are set out in section 5B(2). The assessment of causal factors that contribute to a disease is not simply relativistic. The threshold question for the purposes of the Act is whether the employment contributes to 'a significant degree' 'that is substantially more than material'. This is the "evaluative threshold below which a causal connection may be disregarded". If the contribution is to a significant degree, it is beside the point that one factor contributes to a greater extent than another. Nor does it matter that factors outside the frame of employment also contribute to a significant degree. The Act does not require employment to be the sole, proximate or dominant cause of an injury." I must be satisfied on the balance of probabilities, that contribution by employment was to a significant degree and it ought not be left in the area of possibility or conjecture. Further, whether employment contributed to a significant degree, is a question of fact to be determined by the Tribunal in each case. (Citations omitted.) 37 Comcare did not criticise these passages. In my opinion the last sentence of the extracted passages foreshadows the Tribunal's later rejection of Mr Brennan's opinion about the degree of contribution from Mrs Reardon's employment, correctly identifying that as a matter of fact for its own determination. 38 In the next paragraph of its reasons, the Tribunal stated (at [38]): A worsening or increase in symptoms of a non-work caused condition may constitute an "aggravation injury" for the purposes of the Act and it is unnecessary for a worsening of pathology to be present. (Citation omitted.) 39 Comcare criticises this passage as containing a "bald assertion" which fails to recognise the qualifications Comcare submits are apparent from Beattie. As the respondent correctly submits, in fact the Tribunal uses the word "may" and in my opinion this passage, read as it should be with the passages which have gone before and which I have extracted at [36] above, demonstrates that the Tribunal understood (referring to Beattie, correctly) it needed to look for not only the requisite degree of aggravation, but also a causal rather than a temporal link with employment. Comcare's fractured leg example is not as one-dimensional as its submissions might suggest. If, for example, a worker was required to work standing for long periods of time on a leg which had been broken (in circumstances having no connection with her employment) then depending on the evidence, there is no reason why it would not be open to the trier of fact to find there was an aggravation to the requisite degree under the SRC Act. 40 I do not accept Comcare's submission that the Tribunal looked to nothing more than a temporal connection between the employment and the worsening of pain or other symptoms. My reasons for this conclusion are apparent from my conclusions on the other questions raised by Comcare, especially at [48]-[49], [62]-[78] and [81]-[83] below.

Question of law 3: irrelevant considerations 41 Comcare submits that the Tribunal took into account matters "relating to the onset of conditions" suffered by Mrs Reardon which were irrelevant to the question whether her employment contributed to an aggravation of her hyperacusis. Although its submissions are not entirely clear on this point, the consideration identified appears to be the onset of hearing loss, tinnitus and hyperacusis suffered by Mrs Reardon. Comcare contends the symptoms at onset were irrelevant to the question whether her employment aggravated the hyperacusis. Comcare contends that, on the evidence, the symptoms of Mrs Reardon's hyperacusis did not continue indefinitely although her hearing loss and tinnitus may have done so. 42 I confess to some difficulty in understanding this submission. Comcare's submissions did not explain how the SRC Act forbade the Tribunal from considering a worker's symptoms at onset of the condition in issue, nor did the submission explain why this was a "consideration" in the sense that term is used in the authorities. 43 Generally, as Mason J said in Minister for Aboriginal Affairs v Peko-Wallsend Ltd [1986] HCA 40; 162 CLR 24 at 39-40, it is the statute to which one looks to determine which (if any) considerations are mandatory, and which are forbidden. The statute, whether expressly or by necessary implication, may locate some matters in one category or the other. See also Abebe v Commonwealth [1999] HCA 14; 197 CLR 510 at 579, per Gummow and Hayne JJ; Coal and Allied Operations Pty Limited v Australian Industrial Relations Commission [2000] HCA 47; 203 CLR 194 at [19]; Plaintiff S156/2013 v Minister for Immigration and Border Protection [2014] HCA 22; 309 ALR 29. Where the statutory power is relatively unconfined, the factors to which a decision-maker can have regard will be wide, limited only by the subject matter, scope and purpose of the relevant statutory provisions: see R v Australian Broadcasting Tribunal; Ex parte 2HD Pty Ltd [1979] HCA 62; 144 CLR 45 at 49-50. It is to the statute one looks to determine whether a matter considered by a decision-maker is "definitely extraneous" to the objects the Parliament intended when it conferred the power: see Water Conservation and Irrigation Commission (NSW) v Browning [1947] HCA 21; 74 CLR 492 at 505. 44 It is apparent from the terms of s 14 of the SRC Act that the matter articulated by Comcare is not a "consideration" for the purposes of s 14 of the SRC Act, let alone one which the provisions make legally irrelevant in the sense of forbidden. The decision-making task in s 14 was described by the Full Court in Lees v Comcare [1999] FCA 753; 56 ALD 84 at [35]: This is not to say that a determination under s 14 is without real significance. Such a determination will involve findings on the following matters. First, that an appropriate notice of injury has been given to the relevant authority as required by s 53 of the Act; secondly, that a claim for compensation has been made as required by s 54 of the Act; thirdly, that the person who made the claim or on whose behalf the claim was made was an "employee" at the time of the alleged injury (ss 4 and 5); fourthly, that the employee suffered an injury (s 4); and finally, that the injury has resulted in death, incapacity for work or impairment. 45 In a claim where the worker contended she suffered from three conditions all of which had some relationship to one another, and the Tribunal was required for the purposes of s 14 of the SRC Act to consider (amongst other things) whether her employment aggravated any one or more of those conditions, it is unsurprising that the Tribunal's reasons incorporate discussion and findings relating to the three conditions in a general sense (see [49]-[52] of the Tribunal's reasons) before descending into particular findings about the aggravation of one of them (hyperacusis): see [53]-[54] of the Tribunal's reasons. It is also unsurprising, and indeed necessary, for the Tribunal to focus on the onset of the hyperacusis, since it was Mrs Reardon's primary case that this condition was entirely caused by workplace noise and her use of headphones at work. The secondary case (and the one on which the Tribunal found in her favour) was that the hyperacusis was aggravated by workplace noise and the use of headphones. In those circumstances, for the Tribunal to consider what occurred during the onset of Mrs Reardon's hyperacusis reveals no legal error. 46 This matter was articulated rather differently in Comcare's submissions before the Tribunal, which were in evidence on the appeal. In those submissions (at [11]), Comcare submitted that the evidence showed the aggravation of Mrs Reardon's hyperacusis was only temporary and did not result in any permanent change to her underlying condition of hyperacusis. Comcare relied on the remarks of Gyles J in Bessey [2001] FCA 266; 32 AAR 508 at [6] and [10], where his Honour said: It has been well settled by a series of decisions starting from Jordan CJ's judgment in Salisbury v Australian Iron & Steel Ltd (1943) 44 SR (NSW) 157, including Darling Island Stevedoring & Lighterage Co Ltd v Hankinson (1967) 117 CLR 19; Asioty v Canberra Abattoir Pty Ltd (1989) 167 CLR 533 and Casarotto v Australian Postal Commission (1989) 10 AAR 191, that if an underlying condition is aggravated, in the sense of been made worse, then any incapacity which results is compensable. On the other hand, if the aggravation is temporary, so that after a time it ceases to have any effect and leaves the underlying condition no worse, then there is no relevant continuing injury causing incapacity. … When the Tribunal's analysis of Australia Post's medico-legal consultants is taken into account it is apparent that, when dealing with spondylosis, the Tribunal misunderstood the nature of aggravation in the legislation. As appears from [25] to [33] of the reasons of the Tribunal, Dr Chen and Dr McGill made it quite clear that the bike riding, whilst increasing the symptom of pain whilst the activity took place (and to that extent aggravating the spondylosis), did not produce any permanent underlying change in the back which, after a very limited period, was as it had been with symptoms entirely related to constitutional degenerative change. If this were correct, the authorities to which I have referred establish that there would be no relevant aggravation of the underlying condition and no incapacity arising therefrom. 47 The Tribunal made an express finding on this submission at [54] of its reasons: The matters included in section 5B(2) of the Act have been considered when giving the reasons above. The authority of Australian Postal Corporation v Bessey has been considered and I am satisfied on the evidence that the worsening of Mrs Reardon's symptoms by employment factors was not transitory, but rather continued indefinitely. (Citation omitted.) 48 I fail to see how the Tribunal could have discharged its task in the circumstances of Mrs Reardon's claim without considering the onset of her hyperacusis, and the way in which it developed. That is because central to her claim was the contention that it developed at work, because of her workplace environment and duties. The Tribunal did not accept this claim entirely, but it could not have dealt with either the causal limb or the aggravation limb without considering the evidence in total. The evidence that Mrs Reardon's symptoms subsided in the evenings, or were not as acute when she was not at work (being the evidence Comcare appears to submit the Tribunal failed to take into account) was a matter of which the Tribunal was cognisant. At [50] it stated: Although Mrs Reardon also said that she experienced symptoms away from work, it was apparent from her evidence that the type and frequency of them, were greater in the workplace. She said words to the effect that "initially I had pressure in my head when using the headsets and then it became pain when using the headsets. 49 As a matter of logic, it would seem self-evident that where the fact-finder has concluded (as the Tribunal did) what was occurring at work for Mrs Reardon (both in terms of workplace noise and the nature of her duties) aggravated her hyperacusis, part of that consideration would involve examining the trajectory of Mrs Reardon's symptoms through a working day, and outside work. This does not mean, contrary to Comcare's submissions, that the condition itself is transitory, rather that its intensity varies depending on what Mrs Reardon is exposed to, which indeed mirrors the findings the Tribunal makes at [53], to which I turn below.

Ground 4: whether the Tribunal made findings without evidence or inappropriate inferences 50 The key factual findings of the Tribunal on why it accepted that Mrs Reardon's hyperacusis was aggravated by her employment, and her workplace conditions, can be found at [53] of the Tribunal's reasons, which I have extracted at [13] above. 51 Comcare submits that these findings were either not supported by the evidence or involved inferences that were not reasonably open on the evidence. 52 However, its submissions are then couched in the language of "it is incorrect …", or it is "at least incomplete, to state" and what follows is, in my opinion, properly characterised as engagement with the Tribunal's fact-finding at a merits level, seeking to persuade the Court why the Tribunal's ultimate conclusions would have been different, if it had viewed the evidence through the lens Comcare submits was the better one. 53 The respondent's submissions answered these criticisms in the following way. 54 In relation to [53(c)] of the Tribunal's reasons, the respondent accurately pointed out that Mr Brennan did accept that workplace noises were capable of making the condition of hyperacusis worse (as the Tribunal found he did). The difference between Mr Brennan and Dr Sharman was the degree of impact that could be attributed to workplace noise. Mr Brennan put it at a much lesser degree. I return to this issue below. 55 In relation to the next seven factual findings at [53] of the Tribunal's reasons, and Comcare's criticism of them, the respondent submits: The matters raised by the applicant in its submissions at paragraph 16(d) do not relate to the respondents "past history of noise exposure outside the workplace" and therefore the finding at 53(d) of the reasons is correct. At paragraph 16(e) of its submissions the applicant appears to concede that the Tribunal's finding at 53(e) is correct. There was no diagnosis formal or otherwise of any condition that has caused the hyperacusis. At most Mr Brennan raised the possibility of an underlying condition such as endolymphatic hydrops. The absence of any diagnosed medical condition of the inner ear capable of explaining the condition is a fact which is capable of informing the Tribunal's ultimate conclusion that the employment was a significant contributor to the aggravation of the hyperacusis. The applicant by its submissions at paragraph 16(f) again appears to concede that the Tribunal's finding at paragraph 53(f) was correct. The applicant's complaint appears to be with the ultimate conclusion reached by the Tribunal. In any event Mr Brennan did not give evidence that non-work related factors triggered Mrs Reardon's symptoms. To the contrary his evidence was on the whole consistent with employment triggering an aggravation of the hyperacusis. The Tribunal's findings at 53(g) of the reasons is not a finding in respect of the respondent but a general observation as to whether hyperacusis can be worsened by workplace noise. This general finding accords with the evidence of Mr Brennan. The applicant at paragraph 16(h) of its submissions appears to concede that the Tribunal's finding at 53(h) is correct. The applicant's complaint appears to be with the Tribunal's ultimate finding that the employment was a significant contributor to the aggravation of the hyperacusis. Mr Brennan's evidence as to the difficulties that the respondent experiences in everyday life relate to the time he saw her i.e. 15 May 2014 and when her hyperacusis was established. The applicant by its submissions at paragraph 16(i) appears to accept that the finding of the Tribunal at 53(i) is correct. The applicant's complaint appears to be with the Tribunal's conclusion that the employment was a significant contributor to the aggravation of the hyperacusis. The Tribunal did not merely rely upon a temporal coincidence in order to make that finding. Again the applicant by its submissions at paragraph 16(j) appears to accept that the Tribunal's finding at 53(j) is correct. The respondent repeats paragraph 41. (Footnotes omitted.) 56 I accept the respondent's submissions. As I have noted above, what Comcare seeks to do is emphasise different evidence, in an attempt to contend that the Tribunal should not have found that the workplace noises and conditions aggravated Mrs Reardon's hyperacusis. That was the very matter consigned to the Tribunal as the merits reviewer. 57 In this context it is worthwhile extracting relevant aspects of Mr Brennan's reports which in my opinion bear out the respondent's submissions that Comcare's real quarrel is with the fact that the Tribunal did not entirely accept Mr Brennan's opinion and determine the review on that basis. 58 In his first report of 7 July 2014, having set out Mrs Reardon's hyperacusis and the testing he carried out, Mr Brennan then proceeded to answer 20 questions he was asked by Comcare. 59 In answer to the question "what is your diagnosis", Mr Brennan stated: This patient suffers from a mild bilateral hearing impairment, tinnitus and excessive sensitivity to sound and noise. 60 There was no dispute that the "excessive sensitivity to sound and noise" is hyperacusis. 61 In this report Mr Brennan also wondered whether Mrs Reardon had an "underlying inner ear disorder" which might have caused her sensitivity to noise, but the Tribunal, as it was entitled to, found she did not have any such condition: see the Tribunal's reasons at [46]-[47]. 62 In answer to one of the questions, Mr Brennan expressed the opinion that Mrs Reardon's "condition" (as he had described it and as I have set it out at [59] above) had been "aggravated by workplace factors to a minor degree". 63 In his further report dated 3 February 2015, in response to a request that he review and comment on, amongst other things, Dr Sharman's report, Mr Brennan said: In regard to Dr Sharman's reports I agree there is certainly a work aggravation contributing to her complaint but I nevertheless remain concerned about the underlying cause for her hearing loss and tinnitus and am not convinced that this has a work related cause despite her level of distress with hyperacusis. I would have thought it reasonable for her to have a CT scan of the temporal bones to exclude any dehiscence of the superior semi-circular canals. I agree with both doctors that her prognosis appears poor. 64 Comcare submitted it was unclear whether Mr Brennan meant by this opinion that there was a work aggravation to Mrs Reardon's hyperacusis. It does not seem this was ever clarified in cross-examination. In my opinion it was open to the Tribunal to read Mr Brennan's opinion about aggravation (as opposed to cause) with the generality in which it was expressed, and to see it as extending to the hyperacusis. 65 Mr Brennan's oral evidence to the Tribunal was to a similar effect, as this exchange demonstrates: What's your view then on whether Mrs Reardon's work or work environment has contributed in any way to the development of her tinnitus?---I think that her hearing loss and her tinnitus have got some other basis and I think that it's possible that work-related noise, which she has found unpleasant, would have aggravated the tinnitus to a - to a minor degree. Moving to Mrs Reardon's hyperacusis, what's your view on whether her work environment has contributed to the onset of her hyperacusis?---Well, it's certainly an unusual event for hyperacusis to develop in a situation of more low-grade chronic irritation as opposed to an intense noise in the ear. But there are many causes for hyperacusis and sometimes it's known that a life stress can bring the hyperacusis to light and, as I've mentioned, many other factors. So I think it's likely that her capacity to tolerate noise in the work environment may have aggravated her hyperacusis to some degree. When you say it has aggravated her hyperacusis is that distinct from having caused her hyperacusis? ---Yes. I - I think that the - the abnormal issue here is that she has a hearing loss and that I think if she has a hearing loss and tinnitus a very commonly associated symptom with it is sensitivity to noise and I think that it - that is, you know, something that she has with the hearing loss and if l think the hearing loss is not related to work I have to have a suspicion that her problems relate to a pre-existing ear complaint. 66 Elsewhere, Mr Brennan said in oral evidence he was "not inclined to significantly blame the work environment". It is fair to say, in my opinion, that it is often difficult to tell from Mr Brennan's evidence whether he is speaking about causation, or aggravation. Whichever it was at various times, it is also apparent that Mr Brennan took the view that Mrs Reardon had some underlying (but currently unidentified and undiagnosed) condition of her inner ear. At the end of his cross-examination by Mr Reardon is the following exchange: Yes. Now, I think you've described in your evidence, and your reports generally, that you think the work factors are a minor aggravating contribution to her presentation?---Yes. How do you assess that? Why do you say "minor" when I'm presented with a person who appears to have been rendered unable to continue in her job?---I'm talking about the contribution from the effect of the workplace, and whether it has really had a material adverse effect, and the way I see it is that she's likely to have an underlying clinical problem that would make her more sensitive to these events in the workplace than a normal person. So I suspect there's a fundamental abnormality. And it hasn't really been pursued. There has been an assumption made that it's just work noise, and work stress - work discomfort - work related problem that has escalated and caused, a, hearing loss, b, tinnitus, and c, hyperacusis, but I'm reluctant to make that decision when there's a pre-existing hearing loss. 67 As the respondent submitted, Mr Brennan's opinion as expressed did not necessarily mean Mrs Reardon's claim must fail. The question remained whether, even if a worker had an underlying condition or sensitivity, her employment had aggravated that condition. That was a question of fact for the Tribunal to determine, and as it said in its reasons at [55], it was not bound by Mr Brennan's characterisation of the effect of Mrs Reardon's employment on the aggravation of her hyperacusis. Nor, as it clearly implicitly recognised, was it bound by any other opinion expressed by Mr Brennan to reach any other particular factual conclusion on the questions the SRC Act reposed in the Tribunal. 68 It should be noted that the main alternative hypothesis advanced by Comcare before the Tribunal for the cause of Mrs Reardon's hearing problems was the fact that she had been in two car accidents where airbags had been deployed. That deployment was accompanied, Comcare contended, by significant noise levels that could have caused Mrs Reardon's hearing problems. The medical evidence did not support this hypothesis, and the Tribunal rejected it, at [28]-[29] of its reasons. 69 On this ground as put by Comcare, it is worth emphasising that the Tribunal had much more than medical evidence before it, and from its reasons, relied on much more than that as well. In the introductory paragraph to its findings, the Tribunal made the following general finding (at [39]): The entirety of the evidence about the nature of the noise in Mrs Reardon's workplace prior to her incapacity, conveys a clear picture that there were many types of noises of varying volumes, some loud (such as the fire/evacuation alarms) and others equivalent to mere conversation (55 to 60 decibels). The evidence portrays a busy and quite noisy workplace. 70 At [13], the Tribunal had found: On the basis of the evidence of all witnesses who gave evidence at the hearing, I am satisfied that the work environment where Mrs Reardon worked during 2011, 2012 and 2013 was noisy. It had various "call bells" which frequently made audible sound during the course of a working day. In addition, there were other sounds, general talking when taking calls, feedback from the headsets/phone calls, radios, and fire alarm and other bells at times, all of which Mrs Reardon was exposed to while at work. 71 In particular, the Tribunal was clearly persuaded by the evidence of Mrs Reardon herself. The respondent took the Court to the following parts of Mrs Reardon's evidence: Could you tell the Tribunal what you mean when you use that phrase "head pressure"? Can you describe what that means to you?---What would be happening is when I used the headsets - and it was only ever when I was at work and when I had the headsets on my head and was talking on the phone. It felt like somebody had gone up to the side of my head and put their wrists into the side of my head and was squeezing it. That's what head pressure felt like. So this is a symptom you say was only associated with the use of headsets, and when you say "talking on the phone", do you mean talking on the phone with a headset? Okay. And so it felt like a squeeze on your head. And the pressure: was it something that would go away once you stopped talking on the phone with a headset, once you took the headset off?---At the beginning it did. At the beginning it did go away when I started - when I would take the headsets off I no longer had the problem, but as time went on it would not go away; it would stay with me, and - - - Okay. And did you ever experience that same symptom of head pressure other than when you were using the headset and phone? Okay. And so can we take it that you haven't been experiencing since you stopped working using that headset and telephone?---Now I get - the hyperacusis kicks in, and I get headaches more so than head pressure. Okay?---The headaches are what I get now. It's a pain. I suppose sometimes it still feels like pressure, but it's more a pain. But that's something distinct or different from what you had described as head pressure. We can safely make a distinction between what you had described as head pressure---?---In early days it was head pressure. Yes?---And then it kept getting more head pressure, head pressure, head pain, pain, pain. Okay?---So it just flowed on from head pressure to pain. And when you say the pain, that's the pain associated with the hyperacusis with the exposure to sound, and that's something you experience with the hyperacusis when exposed to noise?---I experience the pain before my hyperacusis was diagnosed--- Yes?------ so it was the head pressure, and then head pressure turned to pain, and then pain - then I was diagnosed with hyperacusis, so - - - Okay?---They all - yes ..... All right. I'm just trying - it's an important distinction for us to understand, if there's difference between what you're describing as head pressure, which is only associated with a headset, and pain that might be associated with hearing sound or headset. Okay?---I've got pain as well. Okay. Are head pressure and a pain associated with a headset? Yes?---Then it went onto head pain when I was on the headset, so it was actually physically painful for me to have them on my head. Okay. And when you stopped using the headset - because you've not been working for some time. Is that correct? So I - we can assume you're not using a headset at all, so you're not experiencing the head pressure that you experienced with a headset?---No. It's more - it's just pain..... So any pain you're experiencing now, if it's caused by anything, it's going to be caused by a noise you're exposed to at home or out in the street or wherever you happen to be, not from wearing a headset. Okay. Now, the pain you've just described that you experience when you're exposed to noise: does that go away after you're - after the noise has stopped, or - how do you experience that?---No. No, my hyperacusis builds up through the day, does not go away. It just compounds. So once my day starts my head usually gets worse. I grow confused. The pain increases. The tinnitus can get louder. It depends if I'm having a bad day or not. That's all right. What do you describe as a bad day? What's a bad day for you?---Now, a bad day for me would be my dogs going off and barking, clanking the pots and pans as I'm cooking. It would be not stopping the microwave from beeping before I get to it, the washing machine beeping. All these things set me off if I'm not fast enough to get to the things before they all move or bark or whatever. That can - that can be a bad day. … I'm asking you whether you agree with that?---I have given so much evidence to show that my headaches came every time I put those headsets on my head, and that I was in pain, and that I told my employer time and time and time again, and I've got so much evidence to show that I told my employer I was in pain every time I put those headsets on my head. So is it your evidence that you don't believe that your motor vehicle accident would have any connection or relationship to the onset of your hearing?---That's not true. I've already mentioned that I acknowledge that the motor vehicle - both motor vehicle accidents could have contributed sensitivity to my hearing, but l did not have hyperacusis in 2012. But by January 2013, I was suffering badly. 72 The Tribunal was obviously persuaded by Mrs Reardon's account. At [49]-[50] of its reasons, it stated: The evidence of Mrs Reardon, is that her symptoms deteriorated and became worse when using the headsets at work and when exposed to the call bell and other noises in the workplace. I accept her evidence and am comforted in doing so because her complaints are corroborated to a degree by contemporaneous records created in the employment relationship. Although Mrs Reardon also said that she experienced symptoms away from work, it was apparent from her evidence that the type and frequency of them, were greater in the workplace. She said words to the effect that "initially I had pressure in my head when using the headsets and then it became pain when using the headsets. 73 In May [2015] FCAFC 93; 322 ALR 330 at [212] the Full Court emphasised that the Tribunal's function does not require it to accept medical opinion on a conclusion which the empowering statute has given to it as fact-finder: … neither the terms of s 4 of the SRC Act, nor the authorities, preclude an injury being established on the basis of an account by a claimant of the disturbances to her or his body or mind, without the necessity for a diagnosis of a recognised medical condition, or corroborating pathology or medical opinion. Whether or not the evidence of a claimant will be sufficient, if it is not supported, corroborated or confirmed by independent medical opinion or pathology, will be a matter for the Tribunal's satisfaction on the evidence in each particular case. The error in the Tribunal's reasoning process at [52] was to proceed on the basis that a claimant's account could never suffice to establish an injury. 74 This approach echoes observations of Brennan J in Repatriation Commission v O'Brien [1985] HCA 10; 155 CLR 422 at 441. 75 The determination of the question of causation, contribution or aggravation by employment for the purposes of the definition of "disease" is in my opinion not subject to any different approach in principle. It remains a determination for the merits reviewer on the evidence and material before it. 76 As to the importance of evidence from Mrs Reardon's co-workers, in the early part of its reasons (see [9]-[13]) the Tribunal set out the lay evidence before it, from Mrs Reardon herself and from her co-workers reaching the conclusion which I have set out at [70] above. 77 Comcare has not persuaded me that any of the findings the Tribunal has set out at [53] of its reasons were made without any probative basis in the evidence before it. What the Tribunal has done, as it was entitled to do as merits reviewer, is carefully assess all of the evidence before it, preferring some evidence over other parts (including deciding to accept Mrs Reardon's evidence about the aggravation of her condition at work), and not placing as much weight on Mr Brennan's evidence and other aspects of the evidence as Comcare contended it should. There is no legal error in the Tribunal taking that course. 78 As the respondent submitted, the Tribunal's finding at [54] of its reasons was a clear finding of worsening of the hyperacusis because of Mrs Reardon's employment (and, specifically, what she was asked to do in her role as an employee). This finding was obviously more than a finding of a temporal connection and is not attended by the legal errors suggested by Comcare on this appeal.

Ground 5: whether the Tribunal erred by failing to address Comcare's submissions 79 This ground concerns a complaint by Comcare that the Tribunal failed to deal with a "submission of substance" advanced by Comcare, and this, it is contended, constitutes an error of law. Reliance is placed on Australian Postal Corporation v Hughes [2009] FCA 1057; 50 AAR 267 at [60], and Dennis Willcox Pty Ltd v Federal Commissioner of Taxation [1988] FCA 123; 79 ALR 267 at 276-277. 80 There is no need in this appeal to explore the nature of the error of law articulated in these cases, although in my respectful opinion it is best characterised as a claim concerning a denial of procedural fairness, and no more than that. 81 This ground relied again on the "fractured leg" analogy which was so evident in many of Comcare's submissions on the appeal. In writing, Comcare submitted: Comcare effectively submitted that employment was merely the setting in which Ms Reardon experienced symptoms of hyperacusis, rather than her suffering an aggravation (or a continuing aggravation) that was significantly contributed to by employment. In other words Ms Reardon's complaints were analogous to a fractured leg encased in plaster such that the requirements of the word 'aggravation' were not fulfilled. Although it might have referred to Beattie in one of its footnotes, the Tribunal failed to deal with Comcare's argument that Ms Reardon experienced the same symptoms whether she was at work or elsewhere. Although the Tribunal might have noted that Ms Reardon experienced symptoms away from work, the Tribunal did not grapple with the case advanced by Comcare. If Comcare's submissions had been accepted then the Tribunal would have concluded that Ms Reardon did not suffer an 'aggravation' (or a continuing aggravation). (Footnotes omitted.) 82 There are two answers to this ground. The first is, as the respondent submitted, that the question for the Tribunal on the second (aggravation) limb was not "where did Mrs Reardon experience her hyperacusis - was it at work or at home?", but rather was employment a material factor or event in aggravating Mrs Reardon's hyperacusis, rendering it symptomatic and ultimately incapacitating. Comcare's contention that Mrs Reardon's workplace was "merely the setting" mistakenly seeks to conflate evidence adduced in cross-examination by Comcare of Mrs Reardon about how her symptoms were presenting in 2015 when she was giving evidence to the Tribunal, and what was responsible for them appearing in the first place, while she was at work. 83 The second, and complete, answer is that the "substantive submission" upon which Comcare relies for this ground was addressed by the Tribunal, which in my opinion understood this was really the core issue of Comcare's dispute with Mrs Reardon's claim on the aggravation limb. 84 In argument on the appeal, counsel for Comcare conceded that paragraph 11.3.6 of Comcare's written submissions to the Tribunal was a "concise" way of putting the submission Comcare now says was not dealt with by the Tribunal. That paragraph stated: Here, when the applicant goes to work with hyperacusis and tinnitus, she will experience the symptoms of those underlying conditions because of noise at work, much as she would experience those symptoms when exposed to noise elsewhere. Any degree of aggravation specifically attributable to work is 'only to a minor degree' (Brennan). 85 What followed this submission was the citation of the two passages from Gyles J's reasons for judgment in Bessey [2001] FCA 266; 32 AAR 508, which I have extracted at [46] above. 86 The submission finds its answer in [52] of the Tribunal's reasons: On the basis of Mrs Reardon's evidence concerning onset of symptoms, which is largely corroborated by the Department's records and witnesses, I am satisfied that the use of the headsets and the noise in the workplace, particularly the call bells caused symptoms of pressure and discomfort from at least 2012 which later developed into pain and headache during the recurring and frequent exposures during work hours throughout late 2012 and into 2013. 87 Unlike Comcare's expression of the issue, the Tribunal correctly identifies the critical question as being what was responsible for the worsening of Mrs Reardon's hyperacusis from 2012, rather than at the time Mrs Reardon was giving evidence before the Tribunal. 88 This ground of appeal must be rejected.

Ground 6: whether the Tribunal failed to provide adequate reasons 89 This ground again invoked the "fractured leg" analogy, and contended that the Tribunal failed to explain in its reasons why it accepted or rejected evidence that was "plainly central to Comcare's case". Comcare contended: The Tribunal did not address the evidence to the effect that Ms Reardon's hyperacusis was analogous to a fractured leg encased in plaster in the sense discussed by the Full Court in the example given in Beattie. That evidence, if it were accepted, was capable of affecting the outcome insofar that the inevitable conclusion would be that Ms Reardon had not suffered an 'aggravation' (or a continuing aggravation). (Footnote omitted.) 90 I have recently set out in Mulligan v National Disability Insurance Agency [2015] FCA 544; 146 ALD 418 at [63]-[65] the approach I consider should be taken to reasons of the Tribunal given pursuant to the obligations in ss 43(2) and (2B) of the Administrative Appeals Tribunal Act 1975 (Cth), and need not repeat those observations. 91 This ground is in my opinion a re-agitation of the same complaint Comcare has made in other ways in its other grounds of appeal. The Tribunal's reasoning process is clear from its statements of reasons. To comply with its obligations under ss 43(2) and (2B) of the Administrative Appeals Tribunal Act it is not required to address every piece of evidence relied on by a party to a review, nor descend into a particular level of detail in how it sets out the evidence and arguments on the review. These are all matters within the Tribunal's discretion. 92 As I pointed out in Repatriation Commission v Holden [2014] FCA 605; 142 ALD 267 at [69], an attack on the reasons of the Tribunal generally presents two issues - first, has there been a failure to comply with the Tribunal's obligation under ss 43(2) and (2B); and secondly, if there has, does such a failure constitute an error of law which justifies setting aside the Tribunal's decision? As the authorities to which I refer in Holden demonstrate, a failure to give adequate reasons may or may not invalidate the Tribunal's decision. In some circumstances, the appropriate relief may only be an order that the Tribunal provide reasons which are compliant with its statutory obligation: see Civil Aviation Safety Authority v Central Aviation Pty Ltd [2009] FCAFC 137; 179 FCR 554 at [55]. 93 The Tribunal's obligation is to set out its findings on material questions of fact. The material questions of fact in Mrs Reardon's review were relatively narrow: what ailments did Mrs Reardon suffer from; did her employment contribute, to a significant degree, to those ailments; alternatively did her employment aggravate those ailments to a significant degree? Comcare's arguments on this ground of appeal did not identify any material question of fact which the Tribunal did not set out in its reasons, in contradistinction to arguing about why the Tribunal should have referred to evidence Comcare considered assisted its arguments and which had been given in cross-examination or examination-in-chief. In general terms, an unsuccessful party to merits review before the Tribunal will usually be able to point to evidence which, if accepted and relied on by the Tribunal, could have resulted in a different outcome for the review. To say that is to do no more than recognise the role of, and choices available to, the Tribunal as fact-finder. 94 The Tribunal's reasons set out its findings on these questions of material fact. As it was obliged to do, the Tribunal then set out the evidence on which those findings were based. As the extract from Minister for Immigration and Border Protection v MZYTS [2013] FCAFC 114; 230 FCR 431 at [49] to which I referred in Mulligan makes clear, the reasons should inform the parties and the reviewing Court of the evidence the Tribunal relied on to reach the factual conclusions it did. Hypothetically, if the reasons omit an entire category of evidence then this might provide a basis for an argument on appeal that the Tribunal did not properly understand or deal with the case as put by a party on review. There is no such wholesale failure here. Comcare's complaint is about the level of detail in the Tribunal's reasons. As I have said, there is no minimum level of detail prescribed by law: in each case, it is a matter of comparing the nature of the Tribunal's obligation under ss 43(2) and (2B) of the Administrative Appeals Tribunal Act with the structure and content of the reasons themselves, in the context of the particular review before the Tribunal. 95 This ground of appeal must be rejected.

Conclusion 96 In my opinion, the Tribunal correctly understood its task in assessing the injuries for which Mrs Reardon claimed compensation. It carefully and independently assessed the medical evidence on both sides: for example, it did not accept Dr Sharman's opinion that Mrs Reardon's employment conditions had caused her hyperacusis. It said (at [45]): On the basis of the medical evidence, I cannot be satisfied that employment was a significant contributing factor to Mrs Reardon's condition of hyperacusis. Dr Sharman attributed the condition to the workplace noise, but close scrutiny of his evidence does not convince me that such attribution is valid. He agreed that the known causes of it were hearing loss, head injury, whiplash, acoustic trauma, an adverse reaction to drugs, chronic ear infection. On the other hand, he agreed that in Mrs Reardon's case the condition appeared to be of gradual onset and not directly attributed to one of the known causes. 97 In expressing its disagreement with the opinion of Mr Brennan about the proportion of contribution that Mrs Reardon's employment conditions played in aggravating her hyperacusis, the Tribunal engaged in an exercise of the same character as that it took at [45] in disagreeing with Dr Sharman's opinion. It examined both medical opinions in the context of the other (non-medical) evidence before it (which it found persuasive) and reached its own conclusion, as was its task. 98 The appeal should be dismissed, with costs. I certify that the preceding ninety-eight (98) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Mortimer.