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 file review was held on November 24, 2022 to consider the worker's appeal.

Issue

Whether or not the claim is acceptable.

Decision

The claim is not acceptable.

Background

The worker filed a Worker Hearing Loss Report with the WCB on February 16, 2022 reporting gradual hearing loss with a slow deterioration over the last 20 years, that they related to their employment with the employer. The worker noted when they began working for the employer, no hearing protection was used but it was required later on.

In discussion with the WCB on February 22, 2022, the worker confirmed they worked for the same employer from 1972 until their retirement in 2001. The worker noted their hearing loss was gradual, with their right ear being worse than their left and worsening in the last four months. The worker advised that in the first two or three years of their employment, the employer did not provide hearing protection but once it was introduced, it was required and worn all the time. The worker noted they worked on a noisy machine for 8 hours per day until they were promoted to a supervisory position where they were still exposed to noise while overseeing staff. The worker further advised they did not undergo regular hearing testing but did have a few hearing tests conducted at work.

On February 28, 2022, the employer submitted an Employer Hearing Loss Report to the WCB indicating the worker was employed from March 20, 1972 until their retirement in 2001 but the employer was not able to provide specific details as to the worker’s job titles as their file was not available. Audiometric testing results for the worker from 1982 to 1999 were included with the employer’s report.

On March 14, 2022, the WCB received a copy of a March 10, 2022 report from the worker’s audiologist, noting the worker attended for an audiologic assessment on February 9, 2022 and that the testing indicated the worker had a “…mild sloping to severe high frequency hearing loss bilaterally.” Further audiological testing on March 22, 2022 indicated the worker had a “…mild, sloping to severe, mixed, high frequency hearing loss, bilaterally” and recommended right and left hearing aids, as outlined in the March 30, 2022 report.

On May 6, 2022, the WCB placed a memorandum to the worker’s file, confirming the worker was employed by the employer for a minimum of 25 years and that information from the employer indicated noise levels of 104 dBA where the worker worked. The WCB confirmed the worker’s claim would meet the threshold criteria for a noise induced hearing loss claim, but that a medical review of the worker’s file was pending.

A WCB audiology consultant reviewed the worker’s file on May 9, 2022 and noted that the hearing assessments for the worker’s right ear indicated a consistent “notch” pattern, which was “…suggestive of NIHL (noise-induced hearing loss), in isolation of other findings.” Further, the audiology consultant noted the assessments noted “consistently poorer” hearing thresholds in the worker’s right ear, with noise-induced hearing loss from occupational noise exposure being typically symmetrical. With respect to the worker’s left ear, the WCB audiology consultant opined there was no consistent “notching” pattern indicated on the hearing assessments, which was not indicative of noise-induced hearing loss.

The WCB advised the worker on May 18, 2022 that the medical evidence did not support that the worker had NIHL, as such hearing loss was typically symmetric, but the worker’s hearing assessments indicated the worker’s hearing was consistently worse in their right ear.

On July 3, 2022, the worker requested reconsideration of the WCB’s decision to Review Office. The worker’s spouse provided an email message in support of the worker’s request on July 4, 2022. Included with the worker’s request was a June 27, 2022 audiogram and a report from the worker’s treating audiologist disagreeing with the WCB audiology consultant’s opinion relating to noise-induced hearing loss typically being symmetrical. The treating audiologist provided copies of audiograms, with identifying information redacted, from other clients who had accepted WCB noise-induced hearing loss claims without a distinct “notch” pattern. On July 11, 2022, the worker provided additional information to Review Office in support of their appeal. A letter in support of the worker’s exposure to loud noise by a former coworker in the employer’s safety department, dated July 11, 2022, was provided. The letter stated the worker, along with other workers, was exposed daily to noxious noise, and that many workers who worked on that jobsite had hearing loss claims. The submission also included a July 11, 2022 chart note from the worker’s treating family physician indicating agreement with the worker’s treating audiologist that asymmetrical noise-induced hearing loss can be consistent with noise exposure and not due to any other medical condition.

Review Office determined on August 30, 2022 that the worker’s claim was not acceptable. Review Office relied upon the opinion of the WCB audiology consultant and noted that asymmetrical hearing loss could occur due to exposure to noxious noise at work when there is an explanation of how one ear would be exposed more compared to the other; however, there was no such explanation evident in the worker’s claim. Further, Review Office found there was consistent evidence of the worker’s hearing loss dating back to 1982 but noted only minimal changes to the worker’s hearing in the 17-year period while the worker worked in the same environment. Review Office also noted the last audiogram the employer provided was within two years of the worker’s retirement and essentially was no different from an audiogram in 1982. Review Office further found the worker reported their hearing had deteriorated in the last four months, as reported by the worker; however, the worker had been retired for over 20 years and that deterioration would not be work related.

The worker filed an appeal with the Appeal Commission on September 8, 2022 and a file review was arranged.

Following the hearing, the appeal panel requested additional medical information prior to discussing the case further. The requested information was later received and was forwarded to the interested parties for comment. On April 4, 2023, the appeal panel met further to discuss the case and render its final decision on the issue under appeal.

Reasons

Applicable Legislation and Policy

The Appeal Commission panels are bound by the provisions of The Workers Compensation Act (the "Act"), regulations under that Act, and the policies established by the WCB's Board of Directors. The provisions of the Act and WCB policies in effect as of the date of the worker’s accident are applicable.

Section 4(1) of the Act provides that where a worker suffers personal injury by accident arising out of and in the course of employment, compensation shall be paid. The Act defines “accident” in s 1(1) as follows:

"accident", subject to subsection (1.1), includes 

(a) a chance event occasioned by a physical or natural cause, 

(b) a wilful and intentional act that is not the act of the worker, or 

(c) an event or condition, or a combination of events or conditions, related to the worker's work or workplace, 

that results in personal injury to a worker, including an occupational disease, post-traumatic stress disorder or an acute reaction to a traumatic event;

The WCB's Board of Directors has established Policy 44.20.50.20, Noise-Induced Hearing Loss (the "Policy"), which provides, in part, that:

“Not all hearing loss is caused by exposure to noise at work. 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.”

Worker’s Position

The worker’s position, as outlined in the Appeal of Claims Decision form, is that the evidence supports a finding that the worker’s hearing loss is noise related. The worker outlined in this form that:

“There is not a time limit for workplace hearing injuries to be reported. It takes time for hearing injuries to deteriorate. It was stated there was some hearing loss by 1982. …Progression over a time is expected. …All reports from hearing professionals seen [who] have advocated on my behalf agree my hearing loss is due to 30 years employment in a high noise related workplace.”

Employer’s Position

The employer did not participate in the appeal.

Analysis

The issue on appeal by the worker is whether their claim is acceptable. For the panel to find that the claim is acceptable, it would have to determine that the worker’s hearing loss resulted from their exposure to noise in the workplace. As detailed in the reasons that follow, the panel was unable to make such a finding and therefore the worker’s appeal is denied.

The panel acknowledges and accepts the evidence of the worker’s bilateral sensorineural hearing loss as well as of their history of workplace noise exposure, but notes that not all hearing loss is caused by or the result of noise exposure in the workplace, and not all workers experience hearing loss from such workplace noise exposure. In this case, the WCB determined that the worker was exposed to noise in the course of their employment with this employer at levels that exceeded the threshold required by the Policy. There is no evidence before the panel to contradict that finding and the panel therefore accepts and relies upon the WCB’s determination in this regard. Further, the panel accepts and relies upon the evidence that the worker was not provided with and did not use hearing protection in the early years of their employment.

The worker’s position is that as a result of their workplace noise exposure at levels above the threshold required by the WCB’s Policy for acceptance of a claim for noise induced hearing loss, they sustained bilateral sensorineural hearing loss. In support of their position, the worker relied upon the reporting from the treating professionals. The panel carefully reviewed the various reports on file. The treating audiologist, in a report dated June 27, 2022 indicated that on the most recent testing, the worker’s results “…were consistent with the previous audiograms” from February and March 2022. The audiologist stated that it is not true that “NIHL from occupational noise is typically symmetrical”, explaining that “As an Au.D., who has worked with all types of noise exposure clients for the past 24 years, noise exposure can be asymmetrical and does not always have a text book noises “notch”. The worker’s treating family doctor noted in a report dated July 11, 2022 that the worker has longstanding bilateral tinnitus and does not report any other “ENT symptoms or signs”. Further, the physician provided their opinion that they would “tend to agree” with the treating audiologist’s conclusion “…that you can have slight asymmetrical hearing loss consistent with noise exposure and not due to any other medical condition.”

The panel also reviewed the audiometric testing results from the workplace for the period of February 1982 through March 1999, noting the evidence that the worker retired from that employment in 2001. Those results suggest right ear hearing loss as of February 1982, with a “notch” pattern evident from 3000 through 8000 Hz. The left ear testing results do not indicate the same pattern, with a notching effect noted only in 1985 and 1989, and overall results indicating less hearing loss in that ear.

The panel considered the May 9, 2022 opinion provided by the WCB audiology consultant who concluded that “There is insufficient evidence to conclude probable NIHL from occupational noise in either ear, given the findings in the left ear, and the unaccounted-for asymmetry between the right and left ears. The panel also considered the March 10, 2023 opinion of the WCB ENT specialist provided upon the panel’s request following the hearing. The ENT specialist, having reviewed the worker’s file, noted that the worker’s exposure to noise in the workplace ended in 2001 upon their retirement. The specialist stated that generally, hearing loss due to noise exposure increases most rapidly during the first 10 to 15 years of noise exposure and does not begin or progress following the end of noise exposure, and as such the workplace hearing test results are relevant in assessing whether the worker has occupational induced NIHL. Further, the specialist noted that the audiogram findings from 2021 and 2022 are not relevant, as they were based on testing more than 20 years following the worker’s last workplace exposure and any deterioration in the worker’s hearing since that exposure would not be medically accounted for in relation to the pre-retirement noise exposure. The ENT specialist also noted that occupational NIHL is “typically bilateral and results in a relatively symmetrical degree of loss as most noise exposures affect both ears symmetrically” and explained that material asymmetry means that there is a greater than 10 dB difference between the right and left ears. With respect to the worker’s claim, the ENT specialist concluded that:

“In view of i) the unilateral audiometric notch pattern affecting the right ear only, and ii) the material asymmetry in the degree of hearing loss between ears in the 1982 to 1999 hearing assessments without an occupational explanation for same, it is concluded that [the worker’s] hearing loss has not been medically accounted for in relation to occupational noise exposure ending in 2001.”

While some asymmetry is acceptable, or not “material” as described by the WCB ENT specialist, the panel accepts that a variation of hearing above 10 dBs, as indicated by the ENT specialist, is material. In other words, when there is a more significant variation between the right and left ears, the difference requires an explanation. Here, the evidence of workplace hearing testing through to 1999 indicates the worker’s asymmetrical hearing loss which is not explained in the evidence before the panel by any occupational cause. More specifically, there is no indication in this case that the worker’s right ear had greater noise exposure which resulted in greater hearing loss in that ear.

While the more recent audiological testing results from 2020 onwards indicate the symmetrical pattern of hearing loss that would be expected, the panel noted that this testing occurred some 20 years after the worker was no longer exposed to noxious noise in their workplace, and as such, these findings cannot be related to the historical workplace noise exposure. The panel also accepts and relies upon the ENT specialist’s opinion in this regard.

On the basis of the totality of the evidence before us and on the standard of a balance of probabilities, the panel finds that the worker’s bilateral sensorineural hearing loss, more likely than not, is not the result of workplace exposure to noise. Therefore, the worker’s claim is not acceptable, and the appeal is denied.

Panel Members

K. Dyck, Presiding Officer
J. Peterson, Commissioner
M. Kernaghan, Commissioner

Recording Secretary, J. Lee

K. Dyck - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 11th day of May, 2023