CHAN CHUN CHEONG v. OCCUPATIONAL DEAFNESS COMPENSATION BOARD

DCOA 1/2005

IN THE DISTRICT COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

OCCUPATIONAL DEAFNESS (COMPENSATION) APPEAL NO. 1 OF 2005

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DCOA 1/2005

IN THE DISTRICT COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

OCCUPATIONAL DEAFNESS (COMPENSATION) APPEAL NO. 1 OF 2005

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JUDGMENT

1.  This is an appeal under the Occupational Deafness (Compensation) Ordinance, Cap. 469, Laws of Hong Kong (“the Ordinance”).

2.  The Ordinance was to provide for (inter alia) the compensation of persons who have been exposed to noise in their working environment and have suffered noise induced deafness. “Noise induced deafness” was defined in Section 2 of the Ordinance to mean sensorineural hearing loss amounting to not less than 40 decibels in each ear; where such loss is due in the case of at least one ear to noise and being the average of hearing losses measured by audiometry over the 1, 2 and 3 kHz frequencies.

3.  The Appellant made an application for compensation to the Occupational Deafness (Compensation) Board (“the Board”) under Section 15 of the Ordinance. The Appellant’s working history and his exposure to noise related work were not in issue. Save for the level of deafness, i.e. whether the Appellant’s deafness in both ears were not less than 40 decibels in each ear, the Appellant’s entitlement to compensation under Section 14(2) of the Ordinance was not contested. Had the Appellant’s application been allowed, he would have received a compensation pay out of $124,631.98 (Average income of $19,233.33 X 72 X 9%).

4.  To qualify for compensation, the Appellant must have sensorineural hearing loss of at least 40 decibels in each of his ears. Sensorineural hearing losses are losses of hearing of the sensorineural nerves or hair cells in the inner ears caused by prolonged exposure to loud noises at work. Deafness not caused by exposure to loud noises at work, e.g. infection of the middle ear or perforation of the ear drum, is not sensorineural hearing loss and is therefore outside the scope of this Ordinance.  Mixed hearing losses could occur where a person has sensorineural hearing losses as well as non-sensorineural hearing losses. For the purpose of determining whether a person is entitled to compensation from the Board, only sensorineural hearing losses are relevant and falls within the definition of Noise induced deafness under the Ordinance.

5.  The Appellant had been given two Pure Tone Audiometry (“PTA”) test by two qualified audiologists of the board.  In conducting PTA test, air conduction test and bone conduction test had been carried out.  In air conduction test, pure tone stimuli at specific frequencies were delivered to the Appellant by headphone. For bone conduction test, the pure tone stimuli was delivered by bone conduction oscillator. In both test, the Appellant was required to make a voluntary response to the tone stimuli he heard. 

6.  The first PTA test on the Appellant was carried out on 11^th June 2004. It was an air conduction test. For the right ear, at 1 kHz, the Appellant ‘s deafness was at 100 decibels, at 2 kHz, it was 110 decibels, and at 3 kHz, it was at 120 decibels. The average of these 3 frequencies was at 110 decibels. For the left ear, at 1 kHz, the Appellant’s deafness exceeds 120 decibels, at 2 kHz, it exceeds 120 decibels, and at 3 kHz, it also exceeds 120 decibels. The average for the left ear therefore exceeds 120 decibels.  In lay man’s term, deafness exceeding 120 decibels is almost total deafness, that is, the person would not be able to hear an aeroplane taking off. The result was not considered reliable by the audiologist and a further PTA was recommended. By observation, I could see that in the course of the trial, the Appellant could hear and follow the proceedings in court. I was sure, the audiologist who tested the Appellant on this occasion was convinced that the Appellant was not co-operating sincerely.

7.  A second PTA test was conducted on the Appellant on 27^th. August 2004. For the right ear, the Appellant had recorded 80 decibels at 1 kHz, 85 decibels at 2 kHz, and 95 decibels at 3 kHz. The average was 86.7 decibels for the right ear. For the left ear, the Appellant had recorded 120 decibels at 1 kHz, 120 decibels at 2 kHz, and 120 decibles at 3 kHz. The average for the left ear was therefore 120 decibels. This PTA test was also unreliable as observed by the audiologist.  The Appellant’s left ear was still almost deaf and his right ear had marked improvement down to 86.7 decibels (from an average of 110 decibels as seen in the first PTA test).

8.  A Cortical Evoked Response Audiometry (“CERA”) was also carried out on the Appellant on this occasion. The CERA did not require the Appellant’s voluntariness to respond to the tone stimuli. The Appellant lied down and had electrodes attached to his head and ears. It was an objective test that recorded down the brain waves of the Appellant in response to different sound frequencies that were input into his ears by headphone. The left and right ears could be tested separately. The following readings were recorded. At 1 kHz, the right ear was 40 and the left ear was only 15. At 2 kHz, the right ear was 55 and the left ear was 20. At 3 kHz, the right ear was 70 and the left ear was 60. The average for the right ear was 55 decibels and the average for the left ear was 31.7 decibels. The CERA test was considered the only reliable test on the Appellant in his application for occupational deafness compensation from the Board.

9.  The Board therefore refused the Appellant’s application for compensation. The reason was that the deafness level in the Appellant’s left ear did not reach the statutory requirement of 40 decibels. The Appellant asked for a review of the determination. The review was also rejected by the Board.

10.  The Appellant appealed against the determination of the Board in rejecting his application. In his Appeal Notice, he asked the Board to give him another test, and his ground of appeal was that the average of the total deafness of both ears, 55 decibels for the right ear and 31.7 decibels for the left ear, was over 40 decibels (55 + 31.7 divided by 2), and as the average of both ears exceeded 40 decibels, his application for compensation should have been allowed.

11.  The Appellant’s ground of appeal was obviously misconceived. The definition of Noise induced deafness under Section 2 of the Ordinance was not that the average of total deafness in both ears should exceed 40 decibels but that the deafness of each ear must not be less than 40 decibels.

12.  Of the three tests conducted by audiologists of the Board on the Appellant, I agree that the two PTA test in which the full co-operation of the Appellant was needed were not reliable and could not be used to determine the level of the Appellant’s deafness in both ears. When I looked at the result of the CERA test on the Appellant, I was surprised to see that it was in fact his right ear (55 decibels) and not his left ear (31.7 decibels) that was more serious in deafness. With the PTA test, the Appellant’s left ear was almost totally deaf. I have no doubt that the Appellant had been exaggerating and not been co-operative. I accept that the CERA test was an accurate and reliable test of the Appellant’s level of deafness in both of his ears.

13.  After lodging the appeal, the Appellant went to see another audiologist, Miss Elizabeth Chua, in March 2006 for further hearing loss test. No CERA test was conducted on the Appellant on this occasion. Impedance Audiometry (“IA”), Distortion Product Otoacoustic Emissions (“DPOAE”) and Auditory Brainstem Response (“ABR”) test were also carried out to determine whether the hearing losses were mixed hearing losses or sensorineural hearing losses. The PTA test conducted on the Appellant by Miss Chua showed that the Appellant right ear average was 60 decibels and the left ear average was 40 decibels. The hearing loss of the Appellant’s left ear found by Miss Chua was in fact a mixed hearing loss. That means the hearing loss was a mixture of sensorineural hearing loss and also middle ear hearing loss that could be due to other reasons. The eardrums in both ears of the Appellant were intact. Miss Chua agreed in cross examination that the other tests (IA, DPOAE, and ABR test) did not actually show the accuracy of the PTA test done on the Appellant. These test merely confirmed that the hearing loss in the Appellant’s left ear was a mixed hearing loss, i.e. hearing loss that occurred in the middle ear coupled with the sensorineural hearing loss in the inner ear of the Appellant. Based on this finding, it was put to Miss Chua in cross examination that if the total of the mixed hearing loss in the Appellant’s left ear was 40 decibels, and there were non sensorineural hearing loss in the middle left ear, that would mean the sensorineural hearing loss in the Appellant’s left ear must be less than 40 decibels. Miss Chua agreed with this analytical conclusion.

14.  The evidence before this court conclusively showed that the Appellant’s left ear did not suffer sensorineural hearing loss of 40 decibels. The CERA test which was a reliable and objective test showed 31.7 decibels that was far short of the 40 decibels to qualify for compensation under the Ordinance. As the requirement of the Ordinance required both ears of the Appellant to have not less than 40 decibels of sensorineural hearing loss, the Appellant ‘s appeal must fail. I therefore dismiss the Appellant’s appeal.

15.  I also order the Appellant to pay the cost of the Respondent for this appeal, to be taxed if not agreed, with certificate for counsel. This cost order is an order nisi to be made absolute in 14 days’ time.