The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

The worker is appealing the decision made by the Workers Compensation Board ("WCB") that their claim is not acceptable. A hearing was held on March 13, 2024 to consider the worker's appeal.

Issue

Whether or not the claim is acceptable.

Decision

The claim is not acceptable.

Background

The worker submitted a Worker Hearing Loss Report to the WCB on February 13, 2023, indicating a gradual hearing loss they related to their employment. The worker was employed in an occupation wherein they were required to operate a locomotive engine. The worker noted hearing protection was not provided until the mid 1980s. On the Work History Summary also submitted, the worker noted they worked with one employer from July 30, 1965 to March 1998, then the second employer from March 1998 until their retirement in April 2006. In both situations, the worker indicated their hearing was “Ok” while working, and they were exposed to locomotive and engine noise in addition to horns.

In a discussion with the WCB on February 22, 2023, the worker advised they first noticed their gradual hearing loss while working for their first employer and noted regular hearing tests were conducted by their employer, which they believed showed their decreased hearing. The worker further advised they began experiencing tinnitus in both ears approximately two years’ previously and were advised by their family physician to have a hearing test conducted. The worker confirmed they retired in 2006 and had not been exposed to noise since that time. They also advised they had a hearing test conducted on February 9, 2023, a copy of which was added to the worker’s file on February 23, 2023 and noted “Right - Borderline normal sloping to mild sensorineural hearing loss. Left – Borderline normal sloping to mild sensorineural hearing loss with mild dip at 250Hz and 1000Hz.” Bilateral tinnitus was noted for the previous 6 months, with exposure to a noisy environment at work for 41 years also indicated. Hearing aids for both ears was recommended.

On March 10, 2023, the second employer provided the WCB with an Employer Hearing Loss Report indicating the worker was employed with them from March 1998 until their retirement on April 30, 2006 and had not reported hearing loss difficulties to them while employed. It was also noted the worker related their hearing loss to working with their first employer. The worker’s first employer submitted an Employer Hearing Loss Report to the WCB on March 20, 2023. It was noted the worker was employed with them from July 20, 1965 until their transfer to the second employer on March 17, 1998. The first employer indicated hearing protection was provided with their hearing protection program starting in 1970. The first employer also submitted audiograms/hearing test results from 1973 to 1997 for the worker.

The worker’s WCB adjudicator placed noise level testing information from the first employer to the worker’s file on March 24, 2023 and from the second employer on March 27, 2023. In addition, the adjudicator placed a memorandum to file on the same date with their rationale for accepting the worker was exposed to noxious noise while at work, with noise levels ranging from 87 to 124 dBA. The adjudicator noted the hearing test results from the first employer stated the worker wore hearing protection approximately 75% of the time they were working and the worker’s hearing up to 1997 appeared normal, except at the 8000Hz level.

For the second employer, the adjudicator noted the information provided indicated the noise level for the worker’s job site was 97.5 dBA, with the worker wearing hearing protection approximately 50% of the time, providing a 3dB of protection. Based on that information, the WCB adjudicator established the worker would have been exposed to noxious noise while employed with both employers and requested a review of the worker’s file by a WCB medical advisor. Hearing test results from the second employer were received by the WCB on April 18, 2023.

The worker’s file was reviewed by a WCB audiology consultant on May 26, 2023. The consultant provided the February 9, 2023 audiogram indicated the worker had noise-induced hearing loss. The consultant further provided the worker’s hearing assessments up to 1999 indicated hearing thresholds “…remained within or returned to within normal limits…” In addition, it was noted a partially legible hearing assessment from August 2001 also found normal hearing thresholds. With respect to the February 9, 2023 audiogram, the WCB audiology consultant found it indicated “This pattern of hearing loss is in keeping with probable NIHL (noise-induced hearing loss), in the context of sufficient confirmed noise exposure.” A low frequency notch was also found at the 1,000 Hz in the worker’s left ear, which was noted to not be typical of NIHL but as opined by the audiology consultant, “…does not preclude the presence of NIHL given the strength of other audiometric findings.”

On May 31, 2023, the WCB advised the worker their claim was accepted for noise-induced hearing loss and approval was given for financial responsibility for bilateral hearing aids.

On August 17, 2023, the second employer’s representative requested reconsideration of the WCB’s decision to accept the worker’s claim to Review Office. The representative presented the worker’s audiograms from 1973 to their retirement indicated their hearing was within normal limits and it wasn’t until the February 9, 2023 audiogram, 17 years after the worker’s 2006 retirement, that noise-induced hearing loss was indicated. The representative noted that typically, hearing loss does not deteriorate after exposure to noxious noise has ended. Further, the employer’s representative noted the worker’s reporting their hearing worsened within the last 2 years, which led them to seek treatment.

Review Office overturned the WCB’s decision on November 2, 2023 and determined the worker’s claim was not acceptable. Review Office noted that it was medically accepted that once exposure to noxious noise stops, so does the damage to an individual’s hearing. Review Office found the audiograms and hearing assessments conducted on the worker did not indicate noise-induced hearing loss until long after their employment and exposure to noxious noise ended and as such, further found the worker’s noise-induced hearing loss is not causally related to their employment and their claim was not acceptable.

The worker filed an appeal with the Appeal Commission on November 15, 2023 and a hearing was arranged.

Reasons

Applicable Legislation and Policy

The panel is bound by The Workers Compensation Act (“the Act”), regulations under the Act, and policies established by the WCB's Board of Directors. The provisions of the Act in effect as of the date of the worker's accident are applicable.

A worker is entitled to benefits under subsection 4(1) of the Act where it is established that the worker was injured as a result of an accident at work.

The WCB's Board of Directors has established Policy 44.20.50.20, Noise-Induced Hearing Loss, ("the NIHL Policy"). The NIHL Policy outlines the WCB's approach to claims arising from long-term exposure to occupational noise that causes hearing loss.

The NIHL Policy provides that a “claim for noise-induced hearing loss is accepted by the WCB when a worker was exposed to hazardous noise at work for a minimum of two years, based generally upon an average of 85 decibels for 8 hours of exposure on a daily basis. For every increase in noise level of 3 decibels, the required exposure time will be reduced by half”.

Employer's Position

The employer was represented by an advocate. The employer’s position relies primarily on the medical records created during the periods that the worker was employed by two different employers (one employer from July 30, 1965 to March 1998, and another employer from March 1998 to April 2006).

The employer takes the position that it is widely accepted in the medical community that once exposure to noxious noise ends, NIHL does not progress. In other words, on the assumption that no further exposure is experienced by the worker, his hearing would not have deteriorated over time.

The worker’s historical audiograms on file were produced from 1973 to 2001. None of the audiograms from this period evidence any hearing loss. On October 28, 2003, the worker filled out an employer issued questionnaire wherein the worker indicated that he did not suffer from loss of hearing or any other hearing related issues.

The only evidence of hearing loss appears in a February 9, 2023, audiogram, taken 17 years after retirement. Furthermore, the worker’s complaints of Tinnitus were only raised as an issue two years ago and became more bothersome in the fall of 2022.

Worker’s Position

The worker primarily relied on his written submissions dated February 13, 2024. The crux of his argument was that he disagrees that hearing loss would be evident in the first two decades of employment. The worker argues that there have been medical studies done on NIHL that purports to show that hearing loss can be immediate, or it can take a long time to be noticeable. It can be temporary or permanent and can affect one ear or both ears. These studies were not submitted for consideration by the panel.

The second argument that the worker relies on is their historical exposure to noise because of the conditions of his employment. The worker spent 41 years operating and riding various types of locomotives. Hearing protection was not provided to him until the 1980s and he provided evidence that in the 1970s, the locomotive operators were not allowed to wear hearing protection out of a concern that they would not be able to hear track torpedoes (a device used as an audio warning signal to locomotive operators).

The third argument that the worker raised during his testimony is that he began to notice a gradual decline in his hearing. It was not an immediate loss, but rather he began to notice difficulty in his hearing, and he was not aware of an alternate explanation which would explain the gradual decline in hearing. The worker confirmed during the hearing that after he retired, he was not engaged in activities that involved loud noises such as being in a music band or partaking in the repeated use of firearms.

Analysis

The issue on appeal is whether the claim is acceptable. To find that the claim is acceptable, the panel would have to determine that the worker has hearing loss that is, on the balance of probabilities, the result of exposure to noise in the workplace. The panel was not able to make such a finding based on the evidence before us, as outlined in the reasons that follow.

It is not in dispute that the worker was exposed to a noxious work environment throughout the duration of his employment. It is also not in dispute that the worker, as of 2023, has a diagnosis of tinnitus, and his right ear suffers from mild sensorineural hearing loss.

While there is evidence of the worker’s mild sensorineural hearing loss on his right ear, and a history of workplace noxious noise exposure, not all hearing loss is caused by or the result of noise exposure in the workplace. Further, not all workers experience hearing loss from such workplace noise exposure.

The panel finds that throughout the years of employment, the worker did have audiograms conducted. The WCB audiology consultant that reviewed these audiograms stated "Hearing thresholds remained within or returned to within normal limits up to the 1999 hearing assessment. A hearing assessment with a partially legible date (possibly Aug 23, 2001) also indicated normal hearing thresholds. No legible hearing assessment records were available after that time until after [the worker's] retirement in 2006."

The evidence also indicates that the worker left their employment in 2006 and there is a lack of evidence of significant noise exposure between that time and the audiological testing in 2023. This is a substantial gap, with no evidence of any testing from 2001 until 2023. The evidence here points to a deterioration in the worker’s hearing after their retirement in 2006 when the worker’s exposure to occupational noise had ended. The panel accepts that hearing loss from noise exposure does not typically progress once such exposure is discontinued, and the evidence here does not reveal any occupational explanation for the deterioration of the worker’s hearing some 16-17 years after leaving a noisy work environment. The panel therefore is unable find a causal relationship between the worker’s post-retirement hearing loss, identified in 2023, and their workplace exposure to noise from 1965 to 2006.

On the basis of the evidence reviewed and heard and on the standard of a balance of probabilities, the panel cannot establish that the worker’s hearing loss was the result of workplace exposure to noise. Therefore, the panel concludes that the claim is not acceptable. The worker’s appeal is dismissed.

Panel Members

R. Mamucud, Presiding Officer
J. Peterson, Commissioner
M. Kernaghan, Commissioner

Recording Secretary, J. Lee

R. Mamucud - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 10th day of May, 2024