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 videoconference hearing was held on May 16, 2023 to consider the worker's appeal.

Issue

Whether or not the claim is acceptable.

Decision

The claim is not acceptable.

Background

On August 19, 2021, the worker filed a Worker Hearing Loss Report with the WCB reporting gradual hearing loss that they noticed within the previous 2 - 5 years and which they related to their employment with the employer. The worker noted they wore hearing protection since the late 1970s to early 1980s and reported ringing in both their ears for the past 6 months for which they had been seeking medical treatment. In the Work History Summary, the worker indicated they began working for the employer in 1974 and experienced progressively declining hearing until retirement in 2006. The worker included an August 16, 2021 audiogram with findings of “…precipitously sloping to moderately-severe wide-notched sensorineural hearing loss, consistent with noise exposure with presbycusis, bilaterally” and recommending bilateral hearing aids.

In discussion with the WCB on September 1, 2021, the worker confirmed they noticed the onset of their hearing problems over the last 2 to 5 years and the constant ringing in their right ear for the past 2 years. The worker stated they advised their family physician about the ringing in their ear and were referred to an Ear, Nose and Throat (ENT) specialist. The worker further confirmed they were exposed to noise 8 hours per day throughout their employment but wore hearing protection for the majority of the time. Further, the worker confirmed they retired in 2006 and had no noise exposure since then.

The employer provided the WCB with an Employer Hearing Loss Report on October 4, 2021. The employer confirmed the worker’s employment began in 1974 and that a hearing protection program started in 1970. The employer also provided a detailed list of the worker’s work history, noting the worker retired on August 1, 2006. The worker’s workplace hearing test results from 1984 to 2002 were also provided. In an email to the WCB, the employer set out their concerns with the worker’s claim, noting the last workplace audiogram from 2002 indicated asymmetric hearing loss, with the worker’s right ear being worse than the left. Further, the employer advised the worker was off work for various periods of time after 2002 and worked in an accommodated position since early 2004.

In the March 24, 2021 report from the treating ENT specialist, provided to the WCB on October 13, 2021, the specialist noted the worker’s report of “…a two-month history of constant, nonpulsatile, right-sided tinnitus” and a two year history of right-sided hearing loss. Audiogram testing by the specialist indicated “…moderate, bilateral, symmetrical sensorineural hearing loss in higher frequencies” and the specialist referred the worker for an MRI study.

A WCB ENT specialist reviewed the worker’s file on October 14, 2021 and noted the audiograms of March 24, 2021 and August 16, 2021 did not appear to agree, and therefore requested the WCB arrange a repeat audiogram. When the worker was tested again on October 20, 2021, the treating audiologist opined the worker sustained “…a clinically significant bilateral hearing impairment of cochlear-neural origin, the pattern of which does resemble sound overexposure. Given [the worker’s] history of industrial noise exposure, it is quite possible that [their] hearing loss, at least in part, is occupational noise induced.” On November 16, 2021, the WCB ENT specialist again reviewed the worker’s file and opined the new October 20, 2021 audiogram was in agreement with the August 16, 2021 audiogram and as such, the earliest audiogram to indicate noise-induced hearing loss in both ears was the August 16, 2021 audiogram.

On October 22, 2021, the WCB requested further information from the employer regarding the worker’s accommodation and on November 18, 2021, the employer advised the WCB that due to an unrelated injury, the worker performed modified duties in a separate room with little to no noise exposure. The WCB advised the worker on November 18, 2021 that their claim was not acceptable. The WCB found the worker was exposed to noxious noise early in their employment with audiological testing indicating noise-induced hearing loss in the worker’s right ear only in 1997, and hearing loss in both ears in 2021. Further, the WCB noted the worker performed modified duties where they were exposed to minimal noise due to an unrelated injury in 1994 until they retired in 2006. Lastly, the WCB noted the audiogram conducted in 2002 before the worker’s retirement found the worker did not require hearing aids.

The worker requested reconsideration of the WCB’s decision to Review Office on December 21, 2021, including a letter of support from the treating audiologist, who reviewed the audiograms provided by the employer and noted discrepancies in the testing results, submitting that this testing was not reliable. The audiologist also noted the worker’s report that while they were performing the modified duties from 1994 to 2006, they were only in a separate room for part of the day, with most of the duties conducted in the same shop area as their initial duties where they were exposed to loud noise. The audiologist concluded that based on the worker’s exposure to noise, their claim for noise-induced hearing loss should be accepted.

On February 11, 2022, the employer provided a submission in support of the WCB’s decision to Review Office, a copy of which was provided to the worker.

On March 3, 2022, Review Office determined the worker’s claim was not acceptable. Review Office found the worker had been employed for approximately 32 years with the employer and had not reported any hearing difficulties to the employer or sought medical treatment for same. Review Office further found the worker wore hearing protection which would have reduced their exposure to loud noise while in the workplace. Review Office relied upon the WCB ENT specialist’s opinion that the first audiogram to indicate noise-induced hearing loss was August 16, 2021, 15 years after the worker’s retirement. Review Office found the evidence did not support the worker’s hearing loss was a result of noxious noise exposure in the workplace and as such, their claim was not acceptable.

The worker’s representative filed an appeal with the Appeal Commission on December 21, 2022 and a hearing was arranged.

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 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" means a chance event occasioned by a physical or natural cause; and includes

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

(b) any 

(i) event arising out of, and in the course of, employment, or 

(ii) thing that is done and the doing of which arises out of, and in the course of, employment, and 

(c) an occupational disease,

and as a result of which a worker is injured.

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 appeared in the hearing represented by a worker advisor and accompanied by a family member as support. The worker advisor made an oral submission on behalf of the worker, and the worker provided testimony in answer to questions posed by the worker advisor and by members of the appeal panel.

The worker’s position is that the evidence confirms that the worker was exposed to noxious noise in the workplace and developed noise induced hearing loss (“NIHL”) as a result of that exposure, which was noted as early as 1989. As such, the worker’s claim should be accepted.

The worker advisor outlined the worker’s job history with the employer, noting that the worker was employed for approximately 32 years until their retirement in 2006, working in a variety of areas. In the early years of that employment, the worker did their job without hearing protection but began to use it when issued by the employer in the late 1970s or early 1980s. The degree of noise in the workplace was such that the worker needed to remove their hearing protection in order to communicate with other workers, which occurred multiple times daily. In 1994, the worker sustained an injury and was placed on modified duties, where they worked in a quiet environment for approximately 4 hours (or half) of each workday, with the balance of the day spent in various areas where noise levels were greater, and the worker would have needed to remove their hearing protection to communicate while doing their work.

The worker advisor noted the evidence that the employer arranged for hearing testing of its workers, and that in 1984, there appeared to be an issue developing in the worker’s left ear at 6000 Hz. The evidence also indicated that in 1989 the worker was sent a letter indicating that recent testing noted “a slight hearing loss” and reminding the worker to use their hearing protection. The employer’s hearing testing program results again indicated hearing loss in 1997, which the WCB audiology ENT confirmed as right ear hearing loss.

The worker advisor submitted that the 2021 audiological findings and report of the audiologist support a finding that the worker’s hearing loss is due to noise exposure in the workplace. The worker advisor relied upon the opinion provided by the treating audiologist that the worker’s noise exposure is a consequence of early occupational noise exposure, interacting with, and accelerating age-related changes to the cochlea. The worker advisor acknowledged that some of the workplace hearing test results yielded “varied results” but argued that it is unfair to disregard all the testing results from during the worker’s employment based on the inconsistent results and noting that there is an “overall trend” of those results showing hearing loss and notches indicative of NIHL as early as the 1980s.

The worker advisor further submitted that the noise survey evidence, submitted on behalf of the worker in advance of the hearing, confirms noise level readings above 85 dBA in most of the work areas where the worker was employed, including one area where readings were in excess of 100 dBA. As the worker was without hearing protection in such environments until the later 1970s or early 1980s, and thereafter, when they had to remove their hearing protection to communicate with coworkers, the worker would have had exposures above the threshold level required by the WCB for noise induced hearing loss claims.

The worker testified to the nature of their work and the circumstances when they needed to remove their hearing protection during the years it was required and provided. The worker confirmed that they used ear plugs. The worker described their duties during the period they were working modified duties, noting that they worked about half of each day in a quiet environment and the other time in various other roles as required. The worker testified that they noticed their hearing loss a long time ago but that they were in denial about it, until family members told them they needed to see a doctor. In response to questions from members of the appeal panel, the worker confirmed that they could not recall any hearing testing prior to 2021, other than the workplace testing.

In sum, the worker’s position is that the evidence supports a finding that the worker’s bilateral hearing loss more likely than not arose out of and in the course of the worker’s employment and as such, the claim should be acceptable.

Employer’s Position

The employer was represented in the hearing by its workers compensation officer, who made an oral submission on behalf of the employer.

The employer’s position is that the claim is not acceptable, and that the worker’s appeal should be denied. The employer’s representative submitted that the evidence indicates that the worker was not exposed to any noxious noise after moving to their accommodated role in 1994 but that when there was noise exposure after that date, the worker had hearing protection to buffer the effects of that noise.

The employer’s representative submitted that the 2002 workplace hearing test results did not indicate a need for bilateral hearing aids, as found by the WCB ENT consultant. Further, from 2002 until their retirement in 2006, the worker continued to work in the accommodated duties without noxious noise exposure and there is no evidence of an increase in or change in the worker’s noise exposure during this period.

The employer’s representative also noted that the evidence indicates the worker did not become aware of their hearing loss until 2-5 years prior to making their claim in 2021, and that this was some 10-15 years post-retirement, suggesting that the worker’s hearing loss first confirmed in 2021 cannot be related to the worker’s employment prior to 2006.

In sum, the employer’s position is that the worker’s claim is not acceptable as the evidence does not support that their NIHL is the result of workplace exposure to noise.

Analysis

The issue on appeal is whether the worker’s claim for noise induced hearing loss as a result of occupational noise exposure is acceptable. For the panel to find that the claim is acceptable, it would have to determine that the worker’s hearing loss was more likely than not caused by their exposure to noise in the workplace. The panel was not able to make such a finding for the reasons that follow.

While there is evidence of the worker’s bilateral sensorineural hearing loss and a history of workplace 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.

In this case, the worker’s position that they were exposed to noxious noise in the workplace throughout their years with the employer is supported by the file evidence and the worker’s testimony as to the nature of the environment in which the worker was employed. The worker’s position is further supported by the noise level reports submitted in advance of the hearing, although it is unclear from the information provided and the submissions made whether the worker was employed in any of these specific areas during the time periods of the noise level testing. The panel also noted the employer’s evidence that a hearing protection program was in place since 1970 as well as the worker’s evidence that they used hearing protection when it was required, which they recalled as beginning in the late 1970s or early 1980s, with the exception of when removed for communication purposes or when working in less noisy environments, such as during the accommodated duties from 1994-2006. The panel finds that it is more likely than not that the worker was exposed to noxious noise in the workplace, but also finds that this exposure was buffered by the worker’s regular use of hearing protection.

The panel noted that the employer conducted periodic hearing tests which the worker participated in. The file records indicate this testing took place in November 1984, June 1988, May 1989, May 1990, May 1991, September 1997, (unknown month) 2000, and October 2002. These testing results were reviewed by the worker’s treating audiologist who noted, in their report dated December 21, 2021, that “The results do show a 6 KHz noise-like notch in the left ear on the 1984 screening, and a mild notched hearing loss for 4-8 KHz for the right ear and a mild notched hearing loss at 6 KHz for the left ear on the 1989 screening….These findings indicate the early stages of noise-induced hearing loss.” The panel noted however that the treating audiologist went on to comment that “If you observe the results across screenings, you can see there is a wide variation in measured thresholds, which suggests the screenings may not have been very valid, which implies that these screenings may not be a reliable indicator of hearing status throughout [the worker’s] working career.”

The treating ENT specialist who assessed the worker on March 24, 2021 noted the worker’s complaint of “a two-month history of constant, nonpulsatile right-sided tinnitus” and the worker’s complaint of right sided hearing loss for two years. The worker’s August 16, 2021 audiogram indicated the worker’s report of bilateral hearing loss for the previous 3-5 years and right ear tinnitus beginning 6 months before that testing. The audiologist concluded the findings indicated “precipitously sloping to moderately-severe wide-notched sensorineural hearing loss consistent with noise exposure with presbycusis, bilaterally.” The October 21, 2021 audiologist report concluded that the worker had “a clinically significant bilateral hearing impairment of cochlear-neural origin, the pattern of which does resemble sound overexposure. Given [their] history of industrial noise exposure, it is quite possible that [the worker’s] hearing loss, at least in part, is occupational noise induced.”

The panel further noted that the WCB ENT consultant determined that the earliest evidence of “signs of NIHL” in the worker’s right ear is from 1997 and that testing at that time did not support the need for a hearing aid. Upon review of the 2021 audiological testing results, the WCB ENT consultant concluded that the October 20, 2021 audiogram “is in agreement with the Aug[ust] 16, 2021 audiogram. Therefore, the earliest audiogram showing signs of NIHL in both ears is dated August 16, 2021.”

In considering whether the evidence supports the worker’s position that they developed NIHL as a result of their occupational noise exposure, the panel noted the variability of results recorded in the workplace hearing testing from 1984 to 2002. We agree with the treating audiologist that the range of findings in the workplace testing does not support the validity or reliability of those results. As such, the panel does not find this testing offers reliable evidence of the worker’s hearing ability or trending changes in the worker’s hearing during that period, and we therefore gave this evidence little weight.

The evidence also indicates that the worker left this employment in 2006 and there is no evidence of significant noise exposure between that time and the audiological testing in 2021. This represents a significant gap in the chronology of the worker’s hearing loss, with no evidence of any testing from 2002 until 2021. While there is evidence that the worker was aware of a hearing loss at some point in the 2-5 years leading up to their testing in March 2021, that would still have been no less than 10 years post-retirement. The evidence here points to a significant 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 10-15 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 2021, and their workplace exposure to noise leading from 1974 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 bilateral sensorineural 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

K. Dyck, Presiding Officer
D. Rhoda, Commissioner
M. Kernaghan, Commissioner

Recording Secretary, J. Lee

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

Signed at Winnipeg this 5th day of June, 2023