1. On 22 July 2025, Paul Knight, the appellant, lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr Kenneth Howison, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on

2 July 2025. 2. The appellant relies on the following grounds of appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act):

(a) the assessment was made on the basis of incorrect criteria, and

(b) the MAC contains a demonstrable error.

1. The delegate is satisfied that, on the face of the application, at least one ground of appeal has been made out. The Appeal Panel has conducted a review of the original medical assessment but limited to the ground(s) of appeal on which the appeal is made.
2. Rule 128 of the Personal Injury Commission Rules 2021 (the PIC Rules) and Procedural Direction PIC7 - Appeals, reviews, reconsiderations and correction of obvious errors in medical disputes set out the practice and procedure in relation to the medical appeal process under s 328 of the 1998 Act. An Appeal Panel determines its own procedures in accordance with r 128(1) of the PIC Rules.
3. The assessment of permanent impairment is conducted in accordance with the SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4th ed

1. On 29 July 2024 the appellant made a claim for lump sum compensation for hearing loss for 11% whole person impairment in accordance with s 66 of the Workers Compensation Act 1987.
2. On 25 March 2025, the respondent's insurer disputed liability for the claim on the basis that the appellant's degree of whole person impairment did not reach the threshold prescribed by s 66(1) of the 1987 Act.
3. On 29 April 2025 the appellant commenced proceedings in the Personal Injury Commission (Commission) and the matter was referred to Medical Assessor Howison for assessment. The Medical Assessor issued a Medical Assessment Certificate on 2 July 2025 assessing the appellant's whole person impairment at 8%.
4. On 23 July 2025 the appellant filed the current appeal from the decision of the Medical Assessor.

1. The Appeal Panel conducted a preliminary review of the original medical assessment in the absence of the parties and in accordance with the Procedural Direction PIC7.
2. As a result of that preliminary review, the Appeal Panel determined that it was not necessary for the worker to undergo a further medical examination because the Appeal Panel had before it sufficient material to determine the appeal.

1. The Appeal Panel has before it all the documents that were sent to the Medical Assessor for the original medical assessment and has taken them into account in making this determination.

1. The parts of the medical certificate given by the Medical Assessor that are relevant to the appeal are set out, where relevant, in the body of this decision.

1. Both parties made written submissions. They are not repeated in full, but have been considered by the Appeal Panel.

1. The procedures on appeal are contained in s 328 of the 1998 Act. The appeal is to be by way of review of the original medical assessment but the review is limited to the grounds of appeal on which the appeal is made.
2. In Campbelltown City Council v Vegan [2006] NSWCA 284 the Court of Appeal held that the Appeal Panel is obliged to give reasons. Where there are disputes of fact it may be necessary to refer to evidence or other material on which findings are based, but the extent to which this is necessary will vary from case to case. Where more than one conclusion is open, it will be necessary to explain why one conclusion is preferred. On the other hand, the reasons need not be extensive or provide a detailed explanation of the criteria applied by the medical professionals in reaching a professional judgement.
3. The appellant relies on four grounds of appeal which the Appeal Panel have considered in turn.

1. The appellant refers to a contradictory paragraph from the Medical Assessment Certificate where the Medical Assessor refers to the qualified opinion of Professor Fagan and states "I disagree with Prof Fagan not making a deduction under Section 323 for Mr Knight's period of employment as a Sole Trader".
2. The appellant correctly submits that when the report of Professor Fagan of 26 February 2025 is reviewed Professor Fagan states "Mr Knight was self-employed from 1978 until 2000. Accordingly a Section 323 deduction of 10% has been made".
3. The appellant submits that this factual error the Medical Assessor "calls into question the credibility of the MA's findings".
4. The Appeal Panel notes the Medical Assessor ultimately assessed a one tenth deduction in accordance with s 323(2) of the 1987 Act.
5. The respondent concedes, going further than the factual error submitted by the appellant, that the Medical Assessor made an error in the application of a deduction under s 323(2) although it is of no material difference as once corrected the appellant's degree of permanent impairment will still be below the threshold to be entitled to lump sum compensation.
6. The Appeal Panel accepts that the misunderstanding by the Medical Assessor of Professor Fagan's opinion is a factual error amounting to a demonstrable error in accordance with s 327(3) of the 1998 Act. The degree to which this factual error infected the Medical Assessor's determination with respect to the s 323 deduction is not clear nor was it subject to submissions. The respondent has nevertheless conceded error with the s 323 deduction applied in the appellant's favour and this needs to be considered by the Appeal Panel on review and corrected if necessary.
7. Section 323 of the 1998 Act provides as follows:

"323 Deduction for previous injury or pre-existing condition or abnormality

(1) In assessing the degree of permanent impairment resulting from an injury, there is to be a deduction for any proportion of the impairment that is due to any previous injury (whether or not it is an injury for which compensation has been paid or is payable under Division 4 of Part 3 of the 1987 Act) or that is due to any pre-existing condition or abnormality.

(2) If the extent of a deduction under this section (or a part of it) will be difficult or costly to determine (because, for example, of the absence of medical evidence), it is to be assumed (for the purpose of avoiding disputation) that the deduction (or the relevant part of it) is 10% of the impairment, unless this assumption is at odds with the available evidence.

(1) If an injury is a loss, or further loss, of hearing which is of such a nature as to be caused by a gradual process, the following provisions have effect -

(a) for the purposes of this Act, the injury shall be deemed to have happened -

(i) where the worker was, at the time when he or she gave notice of the injury, employed in an employment to the nature of which the injury was due - at the time when the notice was given, or

(ii) where the worker was not so employed at the time when he or she gave notice of the injury - on the last day on which the worker was employed in an employment to the nature of which the injury was due before he or she gave the notice,

(b) the provisions of section 61 of the 1998 Act shall apply to or in respect of the injury as if the words 'as soon as practicable after the injury happened and before the worker has voluntarily left the employment in which the worker was at the time of the injury' were omitted therefrom,

(c) compensation is payable by -

(i) where the worker was employed by an employer in an employment to the nature of which the injury was due at the time he or she gave notice of the injury - that employer, or

(ii) where the worker was not so employed - the last employer by whom the worker was employed in an employment to the nature of which the injury was due before he or she gave the notice,

1. As discussed by the Court of Appeal in Rico Pty Ltd v Roads and Traffic Authority (1992) 28 NSWLR 679, 869-690 (Rico) an injury for industrial deafness proceeds on the basis of a number of assumptions. Sheller JA said at [15]:

"The legislative scheme for awards of compensation for boilermaker's deafness proceeds on the following assumptions or fictions:

1. The condition known as 'boilermaker's deafness' is deemed to be a loss of hearing which is of such a nature as to be caused by a gradual process (s 17(2)).
2. A loss of hearing which is of such a nature as to be caused by a gradual process is an injury (s 17(1)).
3. In the language of Barwick CJ, in Commissioner for Railways v Bain the injury is taken to have happened 'as it were, in one blow'. If the worker was, at the time when he or she gave notice of the injury, employed in an employment to the nature of which the injury was due, the injury is deemed to have happened at the time when the notice of the injury was given; if the worker was not so employed, when he or she gave notice of the injury, the injury is deemed to have happened on the last day on which the worker was employed in such employment, before he or she gave the notice (s 17(1)(a)"
4. His Honour said:

"Section 17 deems the injury here suffered to have happened at a particular time for the purposes of the Act. The time the injury actually happened is irrelevant. Clause 2 of Pt 6 limits the application of s 67 to injuries received after a particular time. The question for decision is whether cl 2 refers to the point of time at which the injuries were actually received or to the deemed or notional point of time prescribed by s 17.

To choose the actual point of time is to depart from the result of an historical development in workers compensation legislation in New South Wales designed, in the case of progressive slow growing industrial or occupational diseases or injuries, to relieve the worker from the daunting forensic task of proving when they occurred and, if they were employment related, by which relevant employer compensation therefor is payable. In the case of loss of hearing caused by a gradual process, s 17 achieves this design by providing that the loss is an injury which happened at a particular arbitrary point of time, making compensation payable upon demonstration that the worker was employed by an employer in an employment to the nature of which the injury was due and fixing a particular employer with liability..."

1. This is consistent with what was said in In A & G Engineering Pty Ltd v Civitarese (1996) 41 NSWLR 41(Civitarese) by Beazley JA (with whom Handley and Sheller JJA agreed) adopting Sheller JA in Rico:

"Counsel for the appellant submitted that upon its true construction, s17(1(c)(ii) should be read as if there were inserted into its provisions the words which are bolded as follows:

(ii) . . .the last employer by whom the worker was employed in an employment to the nature of which the injury was due but only if the last such employment was in New South Wales before he or she gave notice.'

Counsel acknowledged that the affect of this construction was that a worker, who had suffered a hearing loss in New South Wales, but whose last noisy employment was with an employer located outside New South Wales could not use the provisions of s 17 to claim compensation from the New South Wales employer. He submitted that the worker, in that case, would be required to prove, through the combined operation of ss4, 9 and 66, the extent of the loss caused by the employment in New South Wales and that the employer against whom the claim was made, actually caused the loss for which the claim was made.

Section 17, as the appellant's case recognised, provides an easy path to compensation for a worker suffering from hearing loss of gradual onset. All that is necessary, under the section is for the worker to prove that the last employment (in respect of which that employer is sued) is one to which the nature of the disease is due. It is not necessary to prove that that employment brought about or contributed to the disease: see Smith v Mann [1932] HCA 30; (1932) 47 CLR 426 at 440; Russo v World Services and Constructions Pty Ltd [1979] 1 NSWLR 330 at 332. As Sheller JA said in Rico Pty Ltd v Road Traffic Authority (1992) 28 NSWLR (1992) 28 NSWLR 679 at 689-690, s 17 proceeds on a series of fictions or assumptions, upon which a worker's entitlement to recover an award under s 66 is based.

In the present case, the last noisy employment was in the Northern Territory. However, the Act does not have extra-territorial operation so as to make T & G Refrigeration liable as the last employer under s 17; see Mynott v Barnard [1939] HCA 13; (1939) 62 CLR 68. That being so, s 17 operates so as to make the appellant the last employer. In other words, the appellant is the last employer to whom the legislation applies and is thus liable to pay compensation. This construction of s 17 is confirmed by this Court's decision in Russo v World Services and Constructions Pty Ltd [1979} 1 NSWLR 330. In that case, the Commonwealth was the last noisy employer and the respondent the noisy employer before that. It was held that, as the Commonwealth was not bound by the provisions of the New South Wales legislation, the respondent was the last noisy employer for the purposes of s17 and thereby liable to pay compensation.

Given the fictional basis upon which s17 proceeds, the construction for which the appellant contends involves the implication of language for which there is not only no warrant, but which runs counter to the very purpose of the section. If follows that the appeal should be dismissed with costs."

1. In OneSteel Ltd v Devine [2012] NSWWCCPD 52 at [48] (Devine) Roche DP in considering Rico said:

"There are many cases where the employer who made only a minimal contribution to the actual hearing loss suffered pays all or most of the compensation awarded. However, there will be many other situations where the same employer will pay no compensation for the hearing loss caused by its employment. That is the nature of a scheme based on assumptions and fictions. It is therefore incorrect to submit that the statutory scheme requires an employer to pay compensation only for those injuries or losses suffered by the worker in that employer's employment."

1. Consistent with what Sheller JA said in Rico, the injury that the Medical Assessor was required to assess as part of the medical dispute under s 319(c) was an injury arising from the assumptions and fictions created by s 17 of the 1987 Act. That injury, with its deemed date, was taken to include all industrial hearing loss as though it was sustained "in one blow".
2. While the appellant's injury is deemed by operation of s 17(1)(a)(ii) to have occurred on

6 November 2021, the actual date of injury is a fiction created by legislation and the time the injury happened is irrelevant. 3. The injury is, in itself, the industrial hearing loss suffered by the appellant. As explained by Sheller JA in Rico, there are clear policy objectives underpinning s 17(1)(b), which creates as a legal fiction, liability in a particular employer, whether or not they are actually responsible for the injured worker's industrial hearing loss. 4. As a result of the legal fiction created by s 17(1) of the 1987 Act "the injury" to be assessed is the appellant's industrial hearing loss, regardless of when it occurred. 5. As the injury is deemed to have occurred "in one blow" on 6 November 2021, there cannot be an applicable s 323 deduction and in applying one the Medical Assessor was in error. 6. This error is easily corrected by the Appeal Panel by simply removing the s 323 deduction increasing the degree of whole person impairment from 8% to 9%.

Ground 2 - the Medical Assessor failed to take into account relevant considerations

1. The appellant refers the Appeal Panel to what was said by Basten JA in Lo v Chief Commissioner of State Revenue [2013 NSWCA 180 at [9] with respect to the term "relevant considerations" and to cl 9.1 of the Guidelines which provides that an assessment by a Medical Assessor "must be based on medical history and ear, nose and throat examination, evaluation of relevant audiological tests, and evaluation of other relevant investigations available to the medical assessor".
2. The appellant refers to a report of Cherry Dolalas, audiologist dated 6 November 2023.
3. The appellant submits that while the clinical examination forms part of a medical assessment, the Medical Assessor did not comment on nor acknowledge the report of

Ms Dolalas. The appellant submitted there was "no active intellectual process" directed at the information, referencing Singh v Minister for Immigration and Multicultural Affairs [2001] FCA 389 at [59]. 4. The appellant submits that in not considering the report of Ms Dolalas the Medical Assessor failed to take into account a relevant consideration and therefore the assessment was made on the basis of incorrect criteria and/or fell into demonstrable error. 5. No submission was made by the appellant as to the actual relevance of the report of

Ms Dolalas from 2023 to the assessment undertaken by the Medical Assessor in July 2025. 6. The respondent submits the Medical Assessor did not refer to the report of Ms Dolalas as the Medical Assessor did not consider it relevant and that the Medical Assessor did refer to other audiological assessments from both the appellant and respondent's qualified medicolegal examiners and obtained a history. The respondent submits the Medical Assessor was not obliged to refer to every document attached to the parties pleadings. 7. The Appeal Panel finds no error with respect to Ground 2. 8. The appellant's reliance on Singh is misconceived. Singh was dealing with a different legislative requirement under s 54 of the Migration Act 1958 (Cth) that prescribes that the "Minister must have regard to all information in application". 9. Clause 9.1 of the Guidelines only require the Medical Assessor to have regard to relevant audiological tests. The appellant has not established that the report of Ms Dolalas was relevant. 10. The Appeal Panel notes that the report results from an audiogram undertaken on

6 September 2023. The report noted asymmetry of hearing loss between the left and right ears and recommended further medical investigation. Following this, on 22 January 2024 the appellant saw his long time treating ENT specialist and had "debris removed from both ears". This occurred again on 13 May 2024 where the specialist recorded "he certainly had a lot". The Appeal Panel notes there has been a history of ear wax accumulation dating back several years. 11. The Medical Assessor had available and considered the reports of Dr Tamhane dated

5 July 2024 which included a thorough examination of the auditory canals and Professor Fagan dated 26 February 2025 who records an examination of the upper respiratory tract and notes the tympanic membrane and tympanic cavities are normal. 12. The assessments by Dr Tamhane and Professor Fagan, considered by the Medical Assessor were more contemporaneous and accompanied by reports of physical examinations in addition to audiological testing. 13. Having regard to the totality of the evidence before the Medical Assessor the Appeal Panel finds no error in the Medical Assessor not considering the report of Ms Dolalas from 2023 as relevant to the assessment of permanent impairment in July 2025 particularly given the ongoing treatment and debris removal since that time.

Ground 3 - the Medical Assessor denied the appellant procedural fairness

1. The appellant's complaint with respect to Ground 3 is again in the context of the alleged failure by the Medical Assessor to consider the report of Ms Dolalas and additionally the applicant's statement.
2. The appellant referred the Appeal Panel to the High Court decision of Kiao v West [1985] HCA 81 and the discussion of Mason J at [33] with respect to procedural fairness.
3. The respondent submits there has been no denial of procedural fairness.
4. As submitted by the respondent, the Appeal Panel does not accept that there has been a denial of procedural fairness. The appellant was provided the opportunity to put material before the Medical Assessor (which he did) and attended an examination with the Medical Assessor where he was provided the opportunity to provide a history and answer relevant questions.
5. For the reasons set out above with respect to Ground 2, the Appeal Panel has already determined that the assessment by Ms Dolalas was not relevant within the context of the available evidence to the issues to be determined by the Medical Assessor. It must follow that the appellant's stated recollection of the assessment with Ms Dolalas is no more relevant that the report itself.
6. The Medical Assessor not discussing material within the decision which is not relevant to the issue in dispute cannot amount to a denial of procedural fairness.
7. The Appeal Panel finds that Ground 3 is not made out.

Ground 4 - The Medical Assessor failed to provide adequate reasons

1. The appellant submits that the Medical Assessor has failed to provide adequate reasons to explain why he accepted his own audiogram over that of Dr Tamhane.
2. The appellant refers the Appeal Panel to what was said with respect to adequate reasons by Basten JA in Vegan at [121]-[122] and the majority in Wingfoot Australia Partners Pty Ltd v Kocak [2013] HCA 34 at [47].
3. The appellant submits that it is not clear how the two audiograms differ and where technical expertise is involved a more detailed explanation was required.
4. The respondent submits there was no error. The Medical Assessor discussed the divergences in his reasons from by Dr Tamhane and Professor Fagan.
5. The respondent refers to Ferguson v State of New South Wales [2017] NSWSC 887 at [23], where Campbell J cited with approval NSW Police Force v Daniel Wark [2012] NSWWCCMA 36:

"...the pre-eminence of the clinical observations cannot be understated. The judgment as to the significance or otherwise of the matters raised in the consultation is very much a matter for assessment by the clinician with the responsibility of conducting his/her enquiries with the applicant face to face..."

1. The respondent submitted the Medical Assessor had provided a viable pathway of reasoning to support his conclusions.
2. Relevantly, the Medical Assessor recorded the following in the Medical Assessment Certificate:

"I based my percentage assessment of binaural hearing loss on the audiogram I carried out on 16 June 2025, the history given by the worker and my clinical examination.'

'In summary, Mr Knight has a whole person impairment of 8%. In making that assessment I have taken account of the following matters:

• The normality of the tympanic membranes,
• The history of noise exposure
• The shape of the audiogram.'

'Noise induced hearing loss is typically bilaterally symmetrical and progressive from the low to the high frequencies and this is because noise damages the inner ear by affecting the higher frequencies first and only with further noise damage are the lower frequencies effected progressively gradually from the higher frequencies to lower frequencies; that is to say 1500 Hz should be affected less than 2000 Hz and 1000 Hz less than 1500 Hz and so on. The progression of hearing loss in the low frequencies needs to be clinically significant if this damage is from exposure to loud noise. Continuous noise exposure over the years is more damaging than interrupted exposure to noise, which permits the ear to have a rest period.

After consideration of the cumulative noise emission levels to which Mr Knight has been exposed and the shape of the audiogram, I would consider that all frequencies in both ears have been damaged by unacceptable noise levels and I have used all frequencies in the calculations for noise induced hearing loss.

As the notional date of injury is after 1 January 2002, calculations have been made based on the National Acoustic Laboratory Tables of 1988. An allowance of 4% for severe tinnitus is indicated.'

I based my percentage assessment of binaural hearing loss on the audiogram I carried out on 16 June 2025, the history given by the worker and my clinical examination."

1. Then, with reference to the other medical opinions the Medical Assessor undertakes the following discussion:

"My audiogram is not the same as the audiogram carried out by Dr Tamhane. I agree with Dr Tamhane that all frequencies have been damaged by loud industrial noise and for using all frequencies in the calculations for noise induced hearing loss. I agree with Dr Tamhane that there is no conduction component to Mr Knight's noise induced hearing loss.

I disagree with Dr Tamhane making a loading of 2% for severe tinnitus, as I feel a loading of 4% for severe tinnitus is indicated from the history received.

I agree with Dr Tamhane making a deduction of 10% for Mr Knight's period of employment as a Sole Trader. I agree with Dr Tamhane that Mr Knight requires bilateral digital hearing aids.

My audiogram is not the same as the audiogram used by Prof Fagan. I disagree with Prof Fagan excluding the frequency 500 Hz in the calculations for noise induced hearing loss. On my audiogram there is no conductive element in the low frequencies and the loss of hearing at 500 Hz is less than at 1000 Hz and this is consistent with noise induced hearing loss. I disagree with Dr Fagan that I could not find any conductive component in Mr Knight's hearing loss. Mr Knight's left sided ear surgery, myringoplasty, has been successful. I agree with Prof Fagan that the left tympanic membrane, the operated eardrum, is normal.

I agree with Prof Fagan that an allowance of 4% is indicated for severe tinnitus. I disagree with Prof Fagan not making a deduction under Section 323 for Mr Knight's period of employment as a Sole Trader."

1. The Appeal Panel accepts that Medical Assessors have an obligation to give adequate reasons for their assessment which demonstrate the actual path of reasoning by which the arrived at their decision. The Medical Assessor however is not required to explain why it did not reach a decision which it did not reach (see Wingfoot at [48], [55]-[56]). Further, the reasons do not need to be extensive (see Vegan at [122]).
2. It is evident from the Medical Assessment Certificate that the Medical Assessor:

(a) carried out an audiogram;

(b) took a history from the appellant;

(c) undertook a clinical examination;

(d) based on (a) to (c) above formed an opinion that the appellant's whole person impairment was 8%;

(e) explained the characteristics of noise induced hearing loss on an audiogram and how this informed his opinion with respect to the appellant, and

(f) engaged with other relevant evidence and in particular the reports and audiograms of Dr Tamhane and Dr Fagan and where and why their opinions differ.

1. The appellant complaints that the Medical Assessor did not explicitly explain why his audiogram is different from that of Dr Tamhane but that complaint is not made out. The Appeal Panel considers it is implicit that the audiogram itself is different because the appellant responded differently to auditory stimuli between the audiogram conducted by

Dr Tamhane and the audiogram conducted by the Medical Assessor. 2. There is no error in the Medical Assessor giving preference to the audiogram he conducted himself as part of his clinical examination over that conducted at an earlier time by another doctor. The Medical Assessor appropriately gave pre-eminence to his own clinical observations and testing undertaken on the day of the assessment (see Wark adopted in Ferguson at [23]). 3. The actual path of reasoning for the conclusions reached by the Medical Assessor is clear from the Medical Assessment Certificate. The Medical Assessor has not failed to provide adequate reasons. Ground 4 is note made out. 4. For the reasons set out above, the Appeal Panel has found error with respect to Ground 1 and the application of a s 323 deduction. 5. The Appeal Panel has determined that the MAC issued on 2 July 2025 should be revoked, and a new MAC should be issued, removing the s 323 deduction. The new certificate is attached to this statement of reasons.

This Certificate is issued pursuant to s 328(5) of the Workplace Injury Management and Workers Compensation Act 1998.

The Appeal Panel revokes the Medical Assessment Certificate of Medical Assessor Howison and issues this new Medical Assessment Certificate as to the matters set out in the Table below:

Table - calculation of whole person impairment (WPI) for industrial deafness as set out in the Table immediately below in accordance with Chapter 9 of the Guidelines for the Evaluation of Permanent Impairment and 1988 NAL Tables:

Resultant total BHI of 17.2% = 9% whole person impairment (Table 9.1)

The above assessment is made in accordance with the SIRA NSW Guidelines for the Evaluation of Permanent Impairment for injuries received after 1 January 2002.