Document name

Hearing Loss

Document number

PRO 11/2012

1. The Workers’ Compensation Board (WCB) has approved POL 11/2012, Injuries – Hearing Loss. This policy provides guidelines for the adjudication of traumatic and occupational noise induced hearing loss claims, as well as PFI awards.
2. Terms referenced in this procedure are defined in POL 11/2012.

1. The Operations staff will gather and review all relevant medical (e.g., all audiograms, past and present) and employment reports to verify occupational noise induced or traumatic hearing loss, including whether there are any non-work-related contributors (e.g., history of ear infections, prior traumatic injury, illness, etc.) affecting the acceptability of a claim.
2. In the case of noise induced hearing loss, staff should examine the medical documentation for typical characteristics of this type of impairment, including the following:
   1. The damage is always sensorineural, affecting the hair cells of the inner ear.
   2. The hearing loss is typically bilateral (affecting both ears).
   3. It almost never produces a loss greater than 75 decibels in high frequencies, and 40 decibels in lower frequencies.
   4. Previous noise exposure does not make the ears more sensitive to future noise exposure and hearing loss does not progress (in excess of what would be expected from age-related threshold shifts) once the exposure is discontinued.
   5. In contrast to age-related hearing impairment, the first sign of noise induced loss occurs at higher frequencies (3000, 4000 or 6000 Hertz) producing a ‘notch, or good hook’ on the audiogram, with better hearing at lower frequencies (500, 1000, and 2000 Hertz).
3. For noise induced hearing loss to be acceptable for a PFI award, the exposure criteria under Point 3 from POL 11/2012, Injuries – Hearing Loss, must be met. Staff may request actual worksite readings from Occupational Health and Safety if sufficient information is not available from the employer, industry or other valid sources to confirm the noise levels. Those claims not meeting the standards outlined in POL 11/2012 will be considered on their own merits.
4. Hearing loss produced by acoustic trauma caused by a single work-related event is generally easier to identify. Normal development of the claim will include gathering information about the circumstances of the incident, including but not limited to:
   1. Whether the worker was wearing appropriate hearing protection (e.g., sudden burst of loud noise causing rupture of the ear drum, excessive pressure or head injury);
   2. Intensity of the noise (sound pressure level);
   3. Type of noise (frequency spectrum);
   4. Character of surroundings in which the noise is produced;
   5. Worker’s distance from the source of the noise;
   6. Position of the ear with respect to sound waves; and
   7. Any relevant medical information including non-work-related causes and treatment following injury.

Staff should note that acoustic trauma can be sensorineural or conductive and usually affects one ear more than the other.

5. Where evidence shows that the worker’s hearing loss arose out of the course of employment, the Operations staff will ensure that an audiogram is performed by a WCB accredited hearing service provider. Hearing service providers will attach a copy of the audiogram to the Primary Level Authorization to Treat – Hearing Services form, which will be submitted to the WCB. The Operations staff will provide approval of the submitted authorization form prior to treatment of the worker (e.g., hearing aids, batteries).
6. Where the worker has already had an audiogram performed, the Operations staff will adjudicate the claim based on the results of that audiogram where the quality of the audiogram is suitable for doing so. Where the results are inconclusive, the Operations staff will arrange for a repeat audiogram by an accredited hearing service provider.
7. Where the Medical Officer or hearing service provider advises that the current audiogram is unsuitable for determining the acceptability of an injury claim, the Operations staff will arrange a repeat audiogram.
8. Although the audiogram may reveal hearing impairment at higher frequencies (4000, 5000 and 6000 Hertz), hearing loss, either traumatic or noise induced, will only warrant a PFI award when there is a decibel sum of the hearing threshold levels (DSHL) totalling 125 or greater in one ear, or 105 or greater in each of both ears. A DSHL totalling 367 in one ear is considered to be a total loss of hearing in that ear.
9. While a worker will not qualify for a PFI award, claim acceptance may be indicated if measurements reveal a DSHL less than 125 in one ear or 105 in each of both ears. Acceptance is dependent on demonstrating some degree of hearing loss attributable to occupational noise exposure or a traumatic work-related injury.
10. If occupational noise exposure or a traumatic work-related injury has resulted in the need for hearing instruments, coverage for the instruments and batteries should be provided in accordance with PRO 57/2017, Hearing Services. Those benefiting from the use of hearing instruments may have a DSHL less than 125 in one ear or 105 in each of both ears, the minimum amount of hearing loss required to qualify for a PFI award. Typically, individuals with a DSHL less than 100 in one ear will not require hearing aids.
11. The Medical Officer and hearing service provider will be contacted if the typical audiometric pattern is not apparent to staff, or other medical information is required to make a decision as to the acceptability of an injury claim.
12. The Medical Officer assigns the PFI rating for tinnitus if there is documented medical evidence from the attending physician, hearing service provider, and or Otolaryngologist that the ringing in the worker’s ears has been long-standing, distressing and continuous for at least two years. Where tinnitus has been caused by a work-related injury or occupational hearing loss, a rating of up to five per cent may be added to the worker’s binaural hearing impairment (hearing impairment of both ears) rating.
13. The WCB will determine the extent of noise induced hearing loss from work-related exposure by reviewing the worker’s audiogram completed while employed or within five years of leaving employment in a high noise industry. Noise induced hearing loss does not progress when noise exposure from work ceases. Therefore, an audiogram completed while employed or within five years of leaving employment would provide an accurate work exposure reading.
14. If no audiogram is available from while the worker is employed or in the immediate five years from leaving employment, the Medical Officer will review the worker’s current audiogram. The Medical Officer will consider audiogram patterns and standard occupational hearing loss calculators when determining the amount of noise induced hearing loss resulting from work-related exposure. However, the claim will not qualify if it is determined that the hearing loss recorded on the current audiogram is predominately age related (presbycusis).
15. Hearing loss claims that are accepted as being predominately noise induced will not have a presbycusis factor deducted in determining the level of the PFI award.
16. Where an interprovincial agreement for occupational noise induced hearing loss exists, the province that initially receives the report of injury is responsible for all costs associated with exposure for parties in the agreement.
17. Except where an interprovincial agreement exists with another jurisdiction, the exposure will be prorated as follows:

18. Injured workers are to be routinely advised of their right to pursue entitlement with other jurisdictions.
19. Charging of costs:
    1. Where there is only one employer, charge to that employer.
    2. Where there is more than one employer within the same industry, charge to that industry by way of a group account established in Employer Services.
    3. Where there is more than one employer and multiple industry groups are involved, charge to the Occupational Disease Reserve.