Document name

Hearing Loss

Document number

PRO 01/2023

1. POL 01/2023, Injuries – Hearing Loss, provides guidelines for the adjudication of traumatic and occupational noise-induced hearing loss claims, as well as PFI awards.

1. What information is required to confirm if hearing loss is considered a compensable work injury? 
   1. 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., noise exposure over time, history of ear infections, prior traumatic injury, illness, etc.).
   2. If it is evident that the worker’s hearing loss arose out of the course of employment:
      1. Operations staff will ensure that an audiogram is performed by a WCB accredited hearing service provider,
      2. Hearing service providers will attach a copy of the audiogram to the Primary Level Authorization to Treat – Hearing Services form and submit to the WCB, and
      3. Operations staff will provide approval to an authorized hearing service provider prior to treatment of the worker.
   3. Operations staff will contact the WCB medical officer if the typical audiometric pattern is not evident to staff or other medical information is required to adjudicate an injury claim.
   4. Operations staff may arrange a repeat audiogram by an accredited hearing service provider if:
      1. The results are inconclusive, or
      2. If the medical officer or hearing service provider advises that the current audiogram is unsuitable for adjudicating an injury claim.

Traumatic hearing loss

2. How do operations staff determine if hearing loss is caused by a work-related traumatic event?
   1. 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. 
      7. Any relevant medical information including non-work-related causes and treatment following injury.
   2. In all cases of acoustic trauma, staff should seek the medical officer’s opinion before an adjudication decision is made.

Noise-induced hearing loss (NIHL)

3. How do operations staff determine if hearing loss is caused by a prolonged occupational noise exposure?
   1. In the case of NIHL, 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 usually does not produce a loss greater than 75 decibels in high frequencies and 40 decibels in lower frequencies.
      4. The hearing loss increases most rapidly during the first 10 to 15 years of exposure.
      5. 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.
      6. 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 and 1000 hertz).
   2. Operations staff will obtain the opinion of the medical officer, as needed, to determine if there is evidence of continuous occupational noise exposure for two or more years equal to or above the decibel levels and durations outlined in point eight of POL 01/2022, Injuries – Hearing Loss. 
   3. Operations staff will obtain the opinion of the medical officer to determine if:
      1. The occupational noise exposure is more likely the dominant cause of the worker’s injury (i.e., having the most significant impact in bringing about the loss).
      2. An audiogram confirms NIHL:
         1. At any time in the worker’s employment years in a high noise industry.
         2. Within five years of leaving employment in a high noise industry (i.e., NIHL does not progress when noise exposure from work ceases), or 
         3. 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. However, the claim will not qualify if the medical officer concludes that it is more likely that NIHL is not the dominant cause of hearing loss on the current audiogram.
   4. In cases where the worker has not been exposed for five years, the WCB medical officer will consider audiogram patterns and standard occupational hearing loss calculators when determining the amount of NIHL resulting from work-related exposure.
4. What if there is NIHL, but hearing loss is worse in one ear (i.e., asymmetrical hearing loss)?
   1. Asymmetrical hearing loss can occur from greater noise exposure on one side or an individual sensitivity difference in each ear. In such cases, when determining the dominant cause, operations staff should consider other factors, such as:
      1. Presbycusis or age-related hearing loss.
      2. Pre-existing conditions from any cause that produces asymmetry in an audiogram. For example:
         1. Noise exposure from recreational activities (e.g., firearm use), and 
         2. Head shadowing (e.g., truck drivers often drive with their window down and the left ear is exposed to greater air pressures than the right ear).
   2. If hearing loss is worse in one ear, and there is NIHL in the better ear, WCB considers that there is an equal NIHL in the worse ear.

Permanent functional impairment (PFI) award

5. How is the PFI rating determined?
   1. PFI always applies to both ears and the rating will be determined in accordance with The American Medical Association Guides to the Evaluation of Permanent Impairment (AMA Guides) and POL 23/2010, Permanent Functional Impairment (PFI) – General. 
   2. 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.
6. How does WCB determine the final PFI rating for NIHL?
   1. As NIHL does not progress when noise exposure from work ceases, the WCB will determine the extent of NIHL 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.
   2. If no audiogram is available from while the worker is employed or in the immediate five years after leaving employment in a high noise industry, the WCB will review the worker’s current audiogram. However, the claim will not qualify if it is determined that it is more likely that NIHL is not the dominant cause of hearing loss on the current audiogram, considering the overall findings and the calculated expected loss from presbycusis (hearing loss due to aging) at the time of the audiogram.
   3. If hearing loss in one ear is worse than the other ear, and there is NIHL in the better ear, WCB considers that there is an equal NIHL in the worse ear, and PFI will apply to both ears.
   4. Hearing loss claims that are accepted as being dominantly noise-induced will not have a presbycusis factor deducted in determining the level of the PFI award.
   5. 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. If 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 (both ears) rating.

Hearing aids

7. When are the costs of hearing aids covered by the WCB?
   1. 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. 
   2. 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. However, they can be provided if the medical officer determines that hearing aids would benefit the worker.
   3. In cases of asymmetric hearing loss accepted as NIHL, basic hearing aids for both ears will be covered if the criteria in subpoint b above are met.
   4. Very severe hearing loss may require special aids (including acoustic implants). For very severe hearing loss due to non-traumatic causes, only basic hearing aids will be provided, as this condition is not related to NIHL. Surgery for implants and the associated risks will not be covered.

Pre-existing conditions

8. What if the worker has pre-existing conditions?
   1. Entitlement for a work-related hearing loss will not be denied due to the existence of a pre-existing condition. However, the WCB does not assume any responsibility for a worker’s pre-existing condition.
   2. The WCB will determine if a work-related noise exposure resulted in either an aggravation or acceleration of a worker’s pre-existing condition in accordance with POL 12/2017, Pre Existing Conditions – Aggravation or Acceleration.

Interjurisdictional exposure

9. What if hearing loss was also due to work-related noise exposure outside Saskatchewan?
   1. 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.
   2. Except where an interprovincial agreement exists with another jurisdiction, the exposure will be prorated as follows:

      

   3. Operations staff will regularly advise injured workers of their right to pursue entitlement with other jurisdictions.

Claim costs

10. How are the costs of hearing loss claims charged?
    1. If there is only one employer, the costs will be charged to that employer.
    2. If there is more than one employer within the same industry, the costs will be charged to that industry by way of a group account established in employer services.
    3. If there is more than one employer and multiple industry groups are involved, the costs will be charged to the occupational disease reserve.