Crowl v Chad Anthony Constructions Pty Limited

[2023] NSWPICMP 186

DETERMINATION OF APPEAL PANEL
CITATION:	Crowl v Chad Anthony Constructions Pty Limited [2023] NSWPICMP 186
APPELLANT:	Bruce Crowl
RESPONDENT:	Chad Anthony Constructions Pty Limited
Appeal Panel
MEMBER:	Richard Perrignon
MEDICAL ASSESSOR:	Henley Harrison
MEDICAL ASSESSOR:	Robert Payten
DATE OF DECISION:	5 May 2023
CATCHWORDS:	wORKERS cOMPENSATION - Appeal from assessment of whole person impairment (binaural hearing impairment); whether Medical Assessor made a deduction for pre-existing condition or abnormality; whether he erred in excluding losses at 1500Hz and below; Held – Medical Assessment Certificate revoked and replaced with new Certificate.

BACKGROUND TO THE APPLICATION TO APPEAL

1. The appellant worker, Mr Crowl, appeals from the Medical Assessment Certificate (MAC) of Medical Assessor Niall dated 23 November 2022.

2. The Medical Assessor assessed a 5% whole person impairment (WPI) (binaural hearing impairment (BHI) of 9.9%) as a result of injury on 30 June 2014 (deemed date). He assessed hearing losses at 1500Hz and below at zero, because he was not satisfied that those losses were caused by noise exposure or other work-related injury.

3. In Table 4 of the MAC, he added together BHI at all frequencies totalling 53.1%. After deducting 29.3% for ‘pre-existing non-related’ losses at 1500Hz and below, and 13.9% for presbycusis, he assessed an adjusted BHI of 9.9%, which converts to 5% WPI.

4. Mr Crowl submits that the deduction of 29.3% for losses at 1500Hz and below:

   (a)was a deduction for a pre-existing condition, which contradicted the Medical Assessor’s finding at [8e] that whether any proportion of the loss was due to a pre-existing injury, abnormality or condition was “undetermined”;

   (b)was arbitrary, not supported by the evidence or the Medical Assessor’s reasons, and

   (c)was inconsistent with his findings that there may have been losses of uncertain aetiology which were “unquantifiable”.

5. He submits that the Medical Assessor erred in failing to consider whether a deduction ought to be made pursuant to s 323 of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act), and to make a deduction of 10% from the total assessed BHI.

6. The Appeal Panel conducted a preliminary review of the MAC in the absence of the parties and in accordance with the NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment (4th edition) (the Guidelines).

Submissions

1. The parties made written submissions which have been taken into account. The appellant’s submissions are summarised above. The respondent submits in summary as follows:

   (a)  The Medical Assessor did not apply a deduction for a pre-existing condition, because he was not satisfied that hearing losses were partly the result of a pre-existing condition or abnormality. He made no deduction from the 5% WPI assessed.

   (b)  The Medical Assessor reasoned that losses below 2000Hz did not result from injury, because losses at 500Hz and 1000Hz were asymmetrical (worse on the left), and losses at 1500Hz were greater than losses at 2000Hz and above. This was part of a proper assessment of impairment resulting from injury. He described these losses as “pre-existing non-related” losses in Table 4 of the MAC.

Reasoning of the Medical Assessor

1. Medical Assessor Niall examined the appellant on 11 May 2022. The appellant was then 82 years of age, having retired in 2003. The Medical Assessor was satisfied that the respondent had employed him in a noisy environment at [4]. He found no evidence of ear disease at [5].

2. He considered that the results of pure tone audiometric testing were unreliable at [6] and [10a], and referred the appellant for cortical evoked response audiometry (CERA) testing and pure tone audiometry (PTA) testing by Ms Winters and C Bruce. At [11], he considered the results of their testing to be reliable, and relied on them as the basis for his assessment. He accepted the PTA results, which were obtained on the same day as the CERA results.

3. No error is alleged in respect of this approach.

4. He reproduced the accepted findings of Winters and Bruce at [6]. They included the following results from the PTA, though he incorrectly labelled them as results from the CERA testing. He made a similar error in Table 4 of the MAC, labelling it “CERA Assessment: 25/10/2022”, instead of “PTA Assessment: 25/10/2022”, though nothing turns on it.

Frequency (Hz)	Left (dB)	Right (dB)
500	45	30
1000	50	50
1500	70	60
2000	60	55
3000	70	65
4000	75	75

1. At [11], he gave the following reasons for finding that losses at 500Hz, 1000Hz and 1500Hz were not noise-induced:

   “The [now accepted responses] show a generally declivitously configured audiometric pattern with bilateral audiometric dips at 1.5 kHz, more salient on the left. At 0.5 and 1kHz the results are worse on the left unlike that which may be seen in NIHL. Losses at 1.5 kHz are greater than is consistent with uncomplicated NIHL and this is made even clearer upon examining the audiometric dips mentioned. Accordingly, I assess that losses below 2 kHz are not due to the injury.”

2. At [8e], in response to the question, “Is any proportion of loss of efficient use or impairment or whole person impairment, due to a pre-existing injury, abnormality or condition?”, the Medical Assessor replied:

   “Undetermined.”

3. In Table 4 of the MAC, he added together the percentage BHI at all frequencies, equalling 53.1% BHI. As indicated, he deducted 29.3% for losses at 1500Hz and below, and 13.9% for presbycusis, yielding 9.9% BHI, which converts to 5% WPI.

Consideration

1. The Appellant submits that the deduction for losses at 1500Hz and below was a deduction pursuant to s 323 of the 1998 Act for a pre-existing injury, abnormality or condition.

2. The MAC and the Medical Assessor’s reasons must be read as a whole. At [8e] the Medical Assessor made it clear that he was unable to determine whether any proportion of the loss was due to a pre-existing injury, abnormality or condition. In those circumstances, we are not satisfied that he intended to make any deduction for such a pre-existing injury, abnormality or condition pursuant to s 323 of the 1998 Act, notwithstanding words he used in Table 4 of the MAC to describe the 29.3% deduction, “Less Pre-existing non-related loss” – emphasis added.

3. On the contrary, he was not satisfied that losses at 1500Hz and below resulted from noise exposure, and for that reason excluded them from his assessment of BHI. It was his task to assess permanent impairment resulting from injury. It formed part of that task to determine which losses resulted from noise exposure, and which did not. It was within his power to find that losses at 1500Hz and below did not result from injury, provided that it was reasonably open on the evidence to do so.

4. In noise induced hearing loss of gradual onset, the lower frequencies are usually preserved and, in the affected frequencies, the severity of the hearing loss increases with increase in frequency until at least 3000 cycles per second (cps). This is because sound enters the inner ear or cochlea at its basal coil where the sound sensitive hair cells responsible for the frequencies 3000 to 6000 cps are situated. Hence in gradual onset noise induced hearing loss, the greatest amount of damaging sound energy affects this region.

5. Adjacent regions of the cochlea can be affected – for instance, hair cells responsible for reception at 2000Hz - but less and less with increasing distance from this region as the energy dissipates with distance.

6. In an audiogram which plots hearing thresholds against frequency (x axis) and sound in decibels (y axis), this produces a V shaped graph, with the dip at the frequency of greatest noise exposure, where the damaging sound energy has entered the ear, and losses decreasing gradually at either side of the dip.

7. That was not the pattern demonstrated here on CERA or PTA testing, because:

   (a)  the losses demonstrated by the PTA at 1500Hz (left 70dB, right 60dB) exceeded the equivalent loss at 2000Hz (left 60dB, right 55dB), and

   (b)  the losses on CERA at 1500Hz (left 70dB, right 65dB) exceeded the equivalent loss at 2000Hz (left 55dB, right 60 dB).

8. In summary, hearing loss at 1500Hz was greater than at 2000Hz, resulting in the dip at 1500Hz. This is not consistent with loss caused by exposure to noise at that frequency, because it does not follow the pattern of noise-induced hearing loss. In our view, there is no basis for finding that the loss at 1500Hz is caused by exposure to noise. It is likely to have been caused by other, unknown factors. There is no pathology or other cause that would affect hearing at 1500Hz without also affecting hearing at the lower frequencies. In our view, hearing losses at 1500Hz and below are unlikely to have been caused by noise exposure.

9. The Medical Assessor found that hearing loss at 1500Hz and below was not caused by noise. Having regard to the pattern of hearing loss elicited on CERA and PTA testing, that finding was reasonably open to him.

10. We note the Medical Assessor’s reasoning at [11] that losses at 500Hz and 1000Hz were worse on the left “unlike that which may be seen in NIHL [noise induced hearing loss]”. It is unnecessary for us to comment on that reasoning, as the shape of the audiogram provided sufficient evidence to exclude losses at 1500Hz and below.

11. No deduction pursuant to s 323 of the 1998 Act is available, as there is no evidence that noise induced losses (ie, losses at 2000Hz and above) resulted from a pre-existing injury, abnormality or condition. We do not understand the appellant to submit that there should be any deduction from hearing impairment at those frequencies.

Conclusion

1. We have found that it was open to the Medical Assessor to find, as he did, that hearing loss at 1500Hz and below was not caused by exposure to noise. On that basis, his assessment of 5% WPI was correct.

2. However, in Table 4 of the MAC, he has described the deduction of 29.3% as “less pre-existing non-related loss” – emphasis added. That is the standard phrase used in the template for such decisions. His description of the non-related loss as ‘pre-existing’ is inconsistent with his reasons at [8e], which indicated that he was unable to determine that there was pre-existing loss. It is also inconsistent with his reasons when read as a whole, which go no further than to find that losses at 1500Hz and below were not caused by noise exposure.

3. The inconsistency between the finding at [8e] that the issue of pre-existing abnormality was ‘undetermined’ and the description of losses at 1500Hz and below Table 4 of the MAC as “pre-existing non-related loss” (emphasis added) demonstrates error on the face of the MAC. That description should be corrected to read, “less non-related loss of 29.3%”.

4. We therefore revoke the MAC and replace it with the attached MAC.

APPEAL PANEL

MEDICAL ASSESSMENT CERTIFICATE

Injuries received after 1 January 2002

Matter Number:	W2173/22
Applicant:	Bruce Crowl
Respondent:	Chad Anthony Constructions Pty Limited

This Certificate is issued pursuant to s 328(5) of the Workplace Injury Management and Workers Compensation Act1998.

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

Audiogram

Injury deemed to have happened on:	Frequency Hz	Left dB HL Air        Bone		Right dB HL Air          Bone		Total % BHI	Occupational % BHI
30.6.2014	500	45	30	4.3	0
1000	50	50	12.1	0
1500	70	60	12.9	0
2000	60	55	8.5	8.5
3000	70	65	7.1	7.1
4000	75	75	8.2	8.2
TOTAL % BHI:  53.1%
Less non-related loss:  29.3%
Less Presbycusis correction:  13.9%
Add % of severe tinnitus:  0.0%
Adjusted total % BHI:  9.9%
Resultant total BHI of 9.9%= 5% whole person impairment (Table 9.1)