Workplace Noise in the Province of Ontario/Worker's Safety and Insurance Board Criteria

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Noise is a serious hazard in many workplaces. Over an extended period of time, if hazardous exposure to noise with machinery and equipment is not eliminated or controlled, it may cause permanent hearing loss and tinnitus.

Exposure to higher levels of noise in the workplace not only results in hearing loss, but also physical and psychological stress, reduced productivity, interferes with communication, and contributes to accidents and injuries by making it difficult to hear potential warning signals. Hearing loss can have a significant impact on the quality of life for individuals affected in addition to their families.

The Workplace Safety and Insurance Board of Ontario estimates that the average cost of hearing aids and batteries for workers with noise-induced loss can reach up to $21,000 every four years. This cost is ongoing from the time that the claim is approved as compensatable until the death of the worker. For example, an individual that is 55 years of age and who lives until the age of 83, would accumulate associated costs that would exceed $100,000. Workers with approved noise-induced loss may also qualify for future economic loss and non-economic loss awards.

Tinnitus, according to WSIB is defined as: the perception of sound (such as ringing or hissing) in the absence of an acoustic stimulus. It is also compensatable when accompanied by noise-induced hearing loss, in workers that are continuously exposed to hazardous noise. Tinnitus is considered to be an occupational disease (under s.2(1) and s.15 of the Workplace Safety and Insurance Act).

Claims for tinnitus are eligible for compensation under these circumstances:

There is an accepted claim for occupational noise-induced hearing loss

There is a clear and adequate history of 2 or more years of continuous and severe tinnitus

The condition has been confirmed by a specialist with facilities for testing tinnitus

WSIB will accept entitlement for occupational noise-induced loss when it is the result of exposure to hazardous noise through employment in the province of Ontario when two circumstances exist.

There is a clear and adequate history of five or more years of exposure to hazardous noise, 90 dB on an "A" weighted scale, for 8 hours a day, or equivalent as per section 139 of Ontario Regulation 488/01 under the Occupational Health and Safety Act.

The average hearing loss of the four speech frequency levels 500, 1,000, 2,000 and 3,000 Hertz in the American National Standards Institute (ANSI) or International Organization for Standardization (ISO) audiometer standards is 25 decibels in each ear.

The exception to the above, as set out by WSIB is as follows:
Since individual susceptibility to noise varies, claims which do not meet the exposure criteria set out above are individually judged on their own merit having regard to the nature of the occupation, extent of exposure, and any other factors peculiar to the individual case.

The following information was obtained through the WSIB website and is provided for your convenience:
 

Guidelines

The WSIB requires a minimum loss of 25 dB in both ears as a result of occupational noise exposure in order to qualify for noise induced hearing loss entitlement.

Permanent disability

Entitlement to health care and/or permanent disability benefits will be considered:

1) when the average hearing loss of the four speech frequency levels (500, 1,000, 2,000, and 3,000 Hertz) in the ANSI or ISO audiometer standards is at least 35 decibels in the worse ear and at least 25 decibels in the better ear

2) for asymmetrical hearing loss when the average hearing loss is 35 decibels in at least one ear but less than 25 decibels in the other, and when the pattern of hearing loss is clearly consistent with occupational noise exposure.

Using the Hearing Loss Permanent Disability Rating Schedule, the decibel measurement of hearing loss is converted to a percentage, which represents the amount of permanent disability. The level of rating is not influenced by any improvement in hearing attained through use of a hearing aid(s).

Permanent disability entitlement is considered to begin on the date notification of the claim is received by the WSIB, however, an entitlement date may be altered if hearing loss prior to that date can be clinically established and confirmed by the adjudicator.

Entitlement under this policy is retroactive to June 3, 1988, or the date of the disability, whichever is later.

Out of Province

If there is a history of out of province occupational noise exposure

1. it is calculated as a percentage of the total exposure
2. the total of the permanent disability award is reduced by this percentage

Non-Compensable Hearing Loss

In the event that a non-compensable hearing loss is identified, the worker's compensable degree of hearing loss will be estimated based on test results.

When the level of a pre-existing, non-compensable hearing loss is known, the permanent disability award will equal the entire hearing loss minus the percentage of the pre-existing non-compensable hearing loss, in accordance with the Hearing Loss Permanent Disability Rating Schedule

Hearing Loss Permanent Disability Rating Schedule

NOTE

1. dB - decibel: measurement of sound intensity.
2. A presbycusis factor (degeneration of hearing due to aging) of 0.5 decibels is deducted for each year that the worker's age exceeds 60.

WSIB Definition

Traumatic hearing loss (THL) is hearing loss of sudden onset experienced after an acute trauma such as*

• exposure to noise from an explosion (acoustic trauma)
• direct trauma to the ear causing damage
• trauma to the head resulting in a severe concussion, or
• exposure to an ototoxic (toxic to the ear) drug or chemical.

*Phaneuf, R. and R. Hetu: An epidemiological perspective of the causes of hearing loss among industrial workers. J. Otolaryngol. 19:31-40, 1990.
 

Assessing permanent impairment

Maximum medical recovery

The WSIB assesses a worker's permanent impairment from traumatic hearing loss when maximum medical recovery (MMR) has occurred (see 11-01-05, Determining Maximum Medical Recovery (MMR)). Since the healing time after a trauma varies considerably - depending on the type of injury - medical confirmation of MMR is needed. A period as long as 6 months to a year may be required to ensure that MMR has occurred.

Rating schedule

The WSIB rates the worker's permanent impairment using the prescribed rating schedule (AMA Guides).** The permanent impairment rating is not affected by any improvement in hearing attained with hearing aids-testing is done without aids. Average hearing losses are never rounded (up or down) before calculating the permanent impairment using the AMA Guides. To determine the final, permanent impairment rating, when more than one, work-related, permanent impairment is present, the WSIB combines the ratings for each impairment, using the AMA Guides Combined Values Chart.

** American Medical Association Guides to the Evaluation of Permanent Impairment, Third Edition (Revised).

NEL & pre-existing hearing loss

To determine the non-economic loss (NEL) benefit for workers who have a documented pre-existing hearing loss, the WSIB uses the most recent pre-injury measurement (e.g., audiogram) so it can subtract the percentage permanent impairment of the pre-existing condition from the percentage of the post injury permanent impairment.

Occupational noise-induced hearing loss

If a worker has pre-existing occupational noise-induced hearing loss (NIHL), the WSIB sets up separate claims: one for the NIHL (see 16-01-03, Occupational Noise-Induced Hearing Loss, and 16-01-04, Noise-Induced Hearing Loss, on/after January 2, 1990); and one for the THL.

Age factor

If a recent pre-injury audiogram is not available, and workers are over 60 years of age, the WSIB applies a factor for presbycusis (age-related hearing loss) by

• determining the average decibel (dB) hearing loss at 4 frequencies (500, 1000, 2000 and 3000Hz), and
• subtracting one-half (0.5) dB from the post-injury permanent hearing loss for every year a worker's age is more than 60.