Cheah v Temperzone Australia Pty Ltd
[2021] NSWPICMP 21
•15 March 2021
| DETERMINATION OF APPEAL PANEL | |
| CITATION: | Cheah v Temperzone Australia Pty Ltd [2021] NSWPICMP 21 |
| APPELLANT: | Tony Cheah |
| RESPONDENT: | Temperzone Australia Pty Ltd |
| APPEAL PANEL: | Ms Jane Peacock Dr Paul Niall Dr Henley Harrison |
| DATE OF DECISION: | 15 March 2021 |
| CATCHWORDS: | WORKERS COMPENSATION- Industrial deafness; the Medical Assessor (MA) is required to approach his assessment on an independent basis; Held- the MA’s reasons were inadequate however his assessment was correct; although the worker has been exposed to occupational noise for 33 years, the audiogram conducted for the assessment did not support the frequencies below 2000 Hz being affected by loud noise; MAC upheld. |
STATEMENT OF REASONS FOR DECISION OF THE APPEAL PANEL IN RELATION TO A MEDICAL DISPUTE
BACKGROUND TO THE APPLICATION TO APPEAL
On 12 November 2020 Mr Tony Cheah (the appellant) lodged an Application to Appeal Against the Decision of Medical Assessor. The medical dispute was assessed by Dr Kenneth Howison, a Medical Assessor (MA), who issued a Medical Assessment Certificate (MAC) on 20 October 2020.
The appellant relies on the following grounds of appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (1998 Act):
· the MAC contains a demonstrable error.
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.
The WorkCover Medical Assessment Guidelines 2006 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 the WorkCover Medical Assessment Guidelines 2006.
The assessment of permanent impairment is conducted in accordance with the NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4th ed 1 April 2016 (the Guidelines) and the American Medical Association Guides to the Evaluation of Permanent Impairment, 5th ed (AMA 5).
PRELIMINARY REVIEW
The Appeal Panel conducted a preliminary review of the original medical assessment in the absence of the parties and in accordance with the WorkCover Medical Assessment Guidelines 2006.
As a result of the Appeal Panel’s preliminary review, the Appeal Panel determined that it was not necessary for the worker to undergo a further medical examination.
EVIDENCE
Documentary evidence
The Appeal Panel has before it all the documents that were sent to the MA for the original medical assessment and has taken them into account in making this determination.
Medical Assessment Certificate
The parts of the medical certificate given by the MA that are relevant to the appeal are set out, where relevant, in the body of this decision.
SUBMISSIONS
Both parties made written submissions. They are not repeated in full but have been considered by the Appeal Panel.
FINDINGS AND REASONS
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.
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.
The following matters were referred for assessment (s 319 of the 1998 Act):
“Date of injury: 02 October 2018 (deemed date)
Body parts/systems referred: Hearing
Method of assessment: Whole person impairment”The MA issued a MAC certifying his assessment as follows:
| Injury deemed to have happened on: | Frequency Hz | Left dB HL Air Bone | Right dB HL Air Bone | Total % BHI | Occupational % BHI | ||
| 02/10/2020 | 500 | 35 | 85 | 7.0 | - | ||
| 1000 | 35 | 90 | 8.9 | - | |||
| 1500 | 40 | 90 | 8.3 | - | |||
| 2000 | 50 | 85 | 8.1 | 7.3 | |||
| 3000 | 55 | 100 | 6.1 | 5.6 | |||
| 4000 | 60 | 105 | 6.5 | 6.0 | |||
| TOTAL % BHI: 44.9 | |||||||
| Less Pre-existing non-related loss: 26.0 | |||||||
| Less Presbyacusis correction: 4.4 | |||||||
| Add % of severe tinnitus: 0.0 | |||||||
| Adjusted total % BHI: 14.5 | |||||||
| Resultant total BHI of 14.5 % = 8.0 % whole person impairment (Table 9.1) | |||||||
The worker appealed.
In summary, the appellant submitted on appeal that the MA made a demonstrable error on two counts as follows:
(a) Failing to include the loss at the lower frequencies; and
(b) Failing to give adequate reasons for his decision to exclude the loss at the lower frequencies.
In summary, Temperzone Australia Pty Ltd (the Respondent) submitted that the MA had not made any demonstrable errors and the MAC should be confirmed.
The role of the MA is to conduct an independent assessment on the day of examination. The MA is required to take a history, conduct a physical examination including an audiogram, review the special investigations, make a diagnosis and have due regard to other evidence and other medical opinion that is before the MA. The MA must bring his clinical expertise to bear and exercise his clinical judgement when making an assessment of impairment and make such assessment in accordance with the criteria in the Guides.
The MA took a history as follows:
“● Brief history of the incident/onset of symptoms and of subsequent related events, including treatment: Mr Cheah has been aware of loss of hearing for many years and has occasional tinnitus.
· Present treatment: Mr Cheah has worn hearing aids for two years.
· Present symptoms: Deafness and tinnitus
· Details of any previous or subsequent accidents, injuries or condition: Mr Cheah has a non-occupational hearing loss of 26.0%. Mr Cheah gave a history of ear surgery to drain fluid from the right ear about twenty years ago. He had no further details of this surgery. He has had severe deafness in the right ear since about that time.
· General health: Mr Cheah has diabetes and has had cardiac stents.
There was no history given of –
§ hereditary deafness
§ acute acoustic trauma
§ severe head injury
§ military service
§ ototoxic drug therapy
§ ototoxic chemical exposure
§ tuberculosis
§ cochleotoxic infection
§ other relevant serious medical conditions
· Work history including previous work history if relevant: Mr Cheah has been employed by Temperzone Australia Pty Ltd from 1990 to the present as an electrical assembler. As such, he describes being exposed to the noise involved in the manufacturing of air-conditioning systems and is therefore exposed to the noise of metal work. Mr Cheah explained that he has to shout above this noise to be heard by colleagues at a distance of one metre and I therefore conclude from this that he was working exposed to an 8-hour equivalent continuous A-weighted sound pressure level of LAeq 90dB(A) or above. This noise level is sufficient as to be responsible for the causation of industrial deafness. I note he has worn ear protection in the latter years of his employment.
Mr Cheah was previously employed as a sole-trader/electrician from 1975-1990 carrying out domestic work and was not exposed to loud noise.
Mr Cheah worked in Malaysia from 1973-1975 for his brother-in-law’s company as a building supervisor and was never exposed to loud noise. Therefore, no deduction under Section 323 is indicated.
Social activities/ADL: Mr Cheah has trouble understanding speech where there is background noise and this causes him to feel socially isolated and have loss of confidence. He also has difficulty with the television and the telephone and problems interacting with friends and family. Mr Cheah’s occasional tinnitus does not interfere with his activities of daily living.”
The MA undertook a physical examination and recorded his findings as follows:
“On examination both tympanic membranes are thickened and scarred. A pure tone audiogram shows a left-sided high tone sensori-neural noise induced hearing loss and a severe mixed loss of hearing in the right ear.
Pure tone audiometry was carried out in a suitable sound treated room that has been tested and shown to meet specifications laid out in AS/NZS 1269 using a calibrated audiometer. I considered the auditory thresholds to be valid and the patient’s responses were repeatable. Please find enclosed a copy of the audiogram.”
The MA summarised his diagnosis as follows:
“● summary of injuries and diagnoses:
Mr Cheah has a binaural high tone sensori-neural noise induced hearing loss.
· consistency of presentation
Mr Cheah’s presentation was consistent with the history given and my clinical examination.”
The MA explained his assessment as follows:
“I based my percentage assessment of binaural hearing loss on the audiogram I carried out on 09 October 2020, the history given by the worker and my clinical examination.
REASONS FOR ASSESSMENT
a. My opinion and assessment of whole person impairment
In summary, Mr Cheah has a binaural high tone sensori-neural noise induced hearing loss of 14.5%, which represents a whole person impairment of 8.0%. This hearing loss is permanent and has reached maximum medical improvement (i.e. when the hearing loss is well stabilised and is unlikely to change substantially in the next year with or without medical treatment).
In making that assessment I have taken account of the following matters:-
o The normality of the tympanic membranes,
o The history of noise exposure,
o The shape of the audiogram.b. An explanation of my calculations (if applicable)
Noise induced hearing loss is typically bilaterally symmetrical and progressive from the low to the high frequencies. After consideration of the cumulative noise emission levels to which Mr Cheah has been exposed, I consider that the frequencies 2000, 3000 and 4000 Hz in the left ear have been damaged by unacceptable noise levels and an equal amount of hearing loss should be allowed for loss of hearing in the right ear in accordance with the WorkCover Guides to the Evaluation of Permanent Impairment 4th Edition, 01 April 2016, page 44, section 9.12.
As the notional date of injury is after 1 January 2002, calculations have been made based on the National Acoustic Laboratory Tables of 1988.
ASSESSMENT OF WPI (Whole Person Impairment)
I have assessed Mr Cheah’s WPI, attributed to his noise induced hearing loss, using the NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment 4th Edition, 01 April 2016.
I have calculated Mr Cheah’s permanent hearing impairment due to industrial deafness, using the recommended Workers Compensation Guidelines.
Assessment of Total Binaural Hearing Impairment
Binaural hearing impairment (section 9.9) = 44.9%
Less presbyacusis correction (section 9.10) = 4.4%
Add loading for severe tinnitus (section 9.11) = 0.0%
Total binaural hearing impairment = 40.5%
WPI (Whole Person Impairment) Table 9.1 = 20.0%Assessment of Occupational Hearing Impairment
Binaural occupational hearing impairment (section 9.9) = 18.9%
Less presbyacusis correction (section 9.10) = 4.4%
Add loading for severe tinnitus (section 9.11) = 0.0%
Total binaural occupational hearing impairment = 14.5%WPI (Whole Person Impairment) Table 9.1 = 8.0%
Assessment of Non-Occupational Hearing Impairment = 26.0%
WPI (Whole Person Impairment) Table 9.1 = 13.0%”A MA is required to make an independent assessment on the day of examination. He is not bound to follow the opinions of the other experts whose reports are in evidence before him. Here the MA explained briefly why his opinion differed from the opinions of the other experts as follows:
“My audiogram is similar to the audiogram carried out by Dr Scoppa. I agree with
Dr Scoppa that the frequencies 2000, 3000 and 4000 Hz in the left ear have been damaged by loud industrial noise and an equal amount of hearing loss should be allowed for the loss of hearing in the right ear. I agree with Dr Scoppa that no allowance for tinnitus is indicated. I also agree with Dr Scoppa that the only possible treatment is with the use of bilateral digital hearing aids.I disagree with Dr Corlette’s statement that no previous ear surgery has occurred, as ear surgery was carried out on the right ear. Mr Cheah did not work in Singapore as stated by Dr Corlette. I disagree with Dr Corlette including the frequencies 1000 and 1500 Hz in the calculations for noise induced hearing loss, as in my opinion the loss of hearing at 1500 Hz in the left ear is more than that at 2000 Hz and this is not consistent with noise induced hearing loss. I agree with Dr Corlette that no deduction for overseas employment is indicated. I agree with Dr Corlette that Mr Cheah would benefit from the use of hearing aids.”
The appellant does not take issue with the MA having taken the “approach of utilising the better ear and an equal amount for the worse ear in calculating the noise induced hearing loss”, However the appellant submits that the MA “made a demonstrable error by failing to include the loss at the lower frequencies of 1.0 and1.5 Hz in the left ear and an equal amount for the right ear.”. The appellant further submitted that the MA erred by failing to give adequate reasons for his decision to exclude the loss at the lower frequencies.
The MA is required to exercise his clinical judgment in respect of the findings on the day of
examination. However, he must adequately explain his reasoning, The Panel considers that the MA’s reasons were not adequate although his assessment of impairment is correct.
Here the MA has stated that he has based his assessment on the normality of the tympanic membranes, the history of noise exposure and the shape of the audiogram. He goes on to state:
“After consideration of the cumulative noise emission levels to which Mr Cheah has been exposed, I consider that the frequencies 2000, 3000 and 4000 Hz in the left ear have been damaged by unacceptable noise levels and an equal amount of hearing loss should be allowed for loss of hearing in the right ear”.
The panel has considered this and agrees with the apportionment, if not the reasons given for it. This is because although according to his own estimate in his statement, the worker has been exposed to occupational noise for 33 years, the audiogram does not support the frequencies below 2000 Hz being affected by loud noise. This, in turn, is because on the left side the MA’s audiogram shows excessive involvement of the frequencies below 2000 Hz and also insufficient difference between 1000 Hz and the frequency 2000 Hz. In his audiogram there is only 5 dB difference between the frequencies 500 and 1000 Hz and the frequency 1500 Hz and then only 10 dB difference between 1500 Hz and 2000Hz, i.e. only 15 dB difference between 1000 Hz and 2000 Hz which is not consistent with occupational hearing loss. The panel therefore considers that despite the lack of clear explanation of the reasons for the frequency determination and an error in his critique of the report of
Dr Corlette, that the MA has correctly apportioned the occupational hearing loss.For these reasons, the Appeal Panel has determined that the Medical Assessment Certificate issued on 20 October 2020 should be confirmed.
Jane Peacock
Member
Dr Paul Niall
Medical Assessor
Dr Henley Harrison
Medical Assessor
15 March 2021
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