The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

The worker is appealing the decision made by the Workers Compensation Board ("WCB") that his claim is not acceptable. A hearing was held on February 25, 2020 to consider the worker's appeal.

Issue

Whether or not the claim is acceptable.

Decision

That the claim is not acceptable.

Background

The worker filed a Worker Hearing Loss Report with the WCB on June 8, 2015, reporting a gradual hearing loss which he attributed to his job duties with the employer. The worker reported that his exposure to noise was occasional and he used hearing protection but did not know when it became available. The worker also reported that he participated in snowmobiling and motorcycling approximately three to five times a week and used power tools at home when needed.

In a discussion with the WCB adjudicator on June 16, 2015, the worker confirmed that he had been employed in the same capacity with the same employer for his whole career. He noted that he was exposed to noise from vehicles, whistles and bells, and felt that his left ear was more exposed as it was closest to the window of the vehicle and they drove with the window open. The worker indicated that he had been snowmobiling and driving a motorcycle for many years and wore a helmet. He shot a gun when he was younger, was a right-handed shooter and wore ear plugs.

Audiograms from 1995, 1997, 1999, 2001, 2004, and June 4, 2015 were received by the WCB. On August 6, 2015, the audiograms were reviewed by the WCB's Ear, Nose and Throat (ENT) consultant, who noted that the first audiogram indicating signs of NIHL in the left ear was in 1995 and in both ears was in 2015. The WCB's ENT consultant opined that the worker had "…an asymmetric hearing loss with the left ear being much worse and dating back to the 1995 audiogram. This can be attributed to the worker's history of right-handed firearm use unless there is an occupational explanation." The consultant stated that the degree of asymmetric hearing loss should be investigated with an MRI to rule out the possibility of an acoustic neuroma. The consultant noted that the worker's hearing loss was not rateable for the purpose of a permanent partial impairment rating, and opined that based on the 1995 audiogram, "…a hearing aid is not needed for the right ear and…the need for a left hearing aid would depend on the cause of the hearing loss (occupational vs non-occupational)."

On August 21, 2015, the WCB's Compensation Services advised the worker that his claim for noise-induced hearing loss ("NIHL") was accepted, but his condition was not considered rateable and he did not qualify for a permanent partial impairment award or hearing aids.

On May 11, 2016, the worker requested that Review Office reconsider Compensation Services' decision. The worker stated that he did not believe his firearm use had any effect on his hearing as his past firearm use was rare, and that the hearing loss on his left side was greater as his left ear was exposed to higher noise levels than his right. On May 12, 2016, Review Office returned the file to Compensation Services to complete further investigation and to arrange for an MRI to rule out an acoustic neuroma.

The MRI, which was performed on November 9, 2016, showed there was no acoustic neuroma, and on November 14, 2016, the WCB's ENT consultant advised that there was no change to his previous hearing assessment. On December 6, 2016, Compensation Services advised the worker that their decision remained unchanged.

On June 1, 2017, the worker renewed his request that Review Office reconsider Compensation Services' decision. The worker again noted that his left ear was exposed to greater noise levels than his right as his job duties required him to work with his left ear facing the window. On July 11, 2017, Review Office provided the worker and the employer with copies of noise level information obtained previously with respect to the worker's occupation, and advised both parties that the issues for reconsideration were being expanded to include whether or not the worker's claim was acceptable.

On August 1, 2017, Review Office determined that the worker's NIHL was not the result of his job duties and his claim was not acceptable. Review Office placed weight on NIHL being typically symmetrical. Review Office noted that the worker's 1995 audiogram indicated NIHL in his left ear only, and it was not until 2015 that NIHL was demonstrated in his right ear. Review Office found that if noise in his work environment was a contributing factor to the worker's hearing loss, it would have affected both ears. Review Office therefore concluded that the worker did not sustain a NIHL injury due to exposure in his work environment. Review Office noted that as the claim was not acceptable, the issues with regard to a permanent partial impairment award and coverage for hearing aids no longer applied.

On April 24, 2018, the WCB received a report from the worker's ENT specialist, and on May 14, 2018, the worker requested that Review Office reconsider their previous decision. On May 22, 2018, Review Office again determined that the worker's claim was not acceptable. Review Office considered the additional medical evidence, but continued to find that the worker's hearing loss was not due to his noise exposure at work. Review Office placed significant weight on their previous opinion that if the noise at work was going to affect the worker's hearing loss "…it would have impacted both of his ears at relatively the same time." Review Office found that the evidence did not support that conclusion.

On June 25, 2019, the worker's union representative submitted further information to Review Office and requested further reconsideration of their decision. On July 11, 2019, Review Office again determined that the worker's claim was not acceptable. Review Office found that the further information supported there were noxious noise levels at work, but observed that not all exposure to harmful levels of noise causes hearing loss. Review Office was again unable to account for the onset of the worker's asymmetrical hearing loss in relation to his work environment.

On September 20, 2019, the worker's representative appealed the Review Office decision to the Appeal Commission and an oral hearing was arranged.

Reasons

Applicable Legislation and Policy

The Appeal Commission and its panels are bound by The Workers Compensation Act (the "Act"), regulations and policies of the WCB's Board of Directors.

Subsections 1(1) and 4(1) of the Act set out the circumstances under which claims for injuries can be accepted by the WCB, and state that the worker must have suffered a personal injury by accident arising out of and in the course of employment. Once such an injury has been established, the worker is entitled to the benefits provided under the Act.

WCB Policy 44.20.50.20, Noise-Induced Hearing Loss (the "Policy"), notes that permanent hearing loss can be caused by either a workplace event (trauma or a single exposure to occupational noise) or prolonged exposure to excessive noise. The Policy outlines the WCB's approach to claims arising from long-term exposure to occupational noise causing hearing loss, where the date of notification of the claim is on or after October 1, 2013. The Policy states, in part, as follows:

3. 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 was assisted by an advocate, who provided a written submission in advance of the hearing and made an oral presentation to the panel, a written copy of which was also provided. The worker's advocate and the worker responded to questions from the panel.

The worker's position was that his repeated exposure to high levels of noxious noise throughout his 37-year career with the employer resulted in his NIHL, and his claim should be accepted.

The worker's advocate submitted that there is clear and convincing evidence that individuals who are employed in the worker's occupation are exposed to noxious noise, which routinely results in NIHL. He submitted that the worker was subjected to these high levels of noise in his work for 37 years.

The advocate referred to a submission to Review Office from the worker's union dated May 1, 2019, in which they had noted that the worker was exposed to extreme noises on a daily basis which more than exceeded the two year requirement of exposure set out in the Policy. He submitted that in four sound tests cited in that submission, dangerously high noise levels of up to 141.2 dBA, with averages ranging from 87 to 91 dBA, were demonstrated. He submitted that the worker "was exposed to these sounds continuously at various degrees of time on a daily basis throughout his entire career." He noted that in 1995, the employer mandated hearing protection in vehicle cabs when windows were open or when riding outside the cab. He submitted that even with that protection, the worker would have been exposed to noise levels in excess of 85 dBA on a daily basis while performing duties inside and outside the cab.

The worker's advocate submitted that a wide body of research supports the conclusion that ongoing repeated exposure to the levels of noise that the worker experienced in this environment are a major contributing cause to hearing loss. He submitted that most NIHL results from continuous exposure to loud sounds, and the level, direction and frequency of repeated exposure are risk factors for NIHL. The advocate referred to various different sources of noise the worker would have been exposed to in the course of his employment.

The advocate submitted that the evidence did not support the WCB's position that the worker's use of a firearm on rare occasions in his early teens was the main contributing factor to the worker's asymmetrical hearing loss. The advocate noted that the worker performed his job duties in the same work environment for 37 years, 17 of which were prior to the implementation of mandatory hearing protection. He submitted that to suggest this rare use of a firearm was more likely to have caused the worker's hearing loss than 37 years of exposure to the excessive volumes of noise at work was ludicrous. The advocate further noted that the worker did not experience notable hearing loss until he was nearly 32 years into his work career, and argued that hearing loss due to rare firearm use in his youth would have been evident long before this.

The worker's advocate submitted that elements of the work environment provided a reasonable explanation for the worker's asymmetrical hearing loss. He stated that while the WCB placed significant weight on the worker's NIHL being asymmetrical and NIHL being typically symmetrical, the WCB did not provide scientific evidence for this opinion. The advocate submitted that there is, however, evidence to the contrary. He noted that one explanation for the asymmetrical hearing loss is that noise levels for an individual in the worker's position were significantly higher on the left side than on the right, due to open windows on the worker's left side. The advocate submitted that studies which the employer provided and were referred to in the union’s May 1, 2019 submission noted that in tests, the left side demonstrated significantly higher levels of exposure than the right and that this would account for the earlier hearing loss in the left ear.

The advocate further submitted that asymmetrical hearing loss is common in occupational NIHL. He stated that while the WCB implied that asymmetry is unusual, there is a growing body of evidence which shows that it is more common than previously thought. He noted that asymmetrical hearing loss may be caused by a number of factors, and the exact nature and contributing factors of NIHL can rarely be known with precise certainty, as there are many things that influence how hearing loss will affect an individual. He submitted that what was known in the worker's case, however, was that he had no indication of hearing damage before he started working for the employer, and experienced hearing loss only after he was repeatedly exposed to noxious noise events over the following 37 years.

Referring to a 2018 study, the advocate submitted that current evidence also shows that an individual's left ear is more susceptible or vulnerable to noise exposure than the right ear, as was the case for the worker.

In conclusion, the worker's advocate submitted that the noxious noise experienced daily during the worker's 37-year career "…meets every standard of evidence as a cause for NIHL." The advocate submitted that the evidence supports the conclusion that both the work environment and greater vulnerability of the left ear are likely explanations for the worker's asymmetrical loss, and his claim is acceptable.

Employer's Position

The employer did not participate in the appeal.

Analysis

The issue before the panel is claim acceptability. The claim has been advanced on the basis of long-term exposure to noxious levels of occupational noise resulting in noise-induced hearing loss. For the worker's appeal to be successful, the panel must find, on a balance of probabilities, that the worker sustained a noise-induced hearing loss due to his exposure to high levels of noxious noise during his employment, as set out in the Policy. The panel is unable to make that finding, for the reasons that follow.

The Policy provides that in order to establish NIHL, a worker must have been exposed to noxious 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 is reduced by half. This is the threshold that must be met. Based on our review and consideration of the evidence before us, the panel is not satisfied that this noise threshold has been met.

Based on the evidence, the panel accepts that the worker suffered noise-induced hearing loss but is unable to find that it was related to the worker's job duties or work environment.

The panel notes that while there is more general information regarding noise levels in the work environment, there is a lack of more specific information as to the noise levels which the worker himself would have been exposed to in the course of his employment on a daily basis. In this regard, the worker's advocate noted that the worker was exposed to different sounds and noise levels "continuously at various degrees of time on a daily basis" throughout his career. In response to questions at the hearing, the worker stated that trips "all vary day to day, every trip is different," and was unable to indicate or estimate, on a daily basis or on average, how much time he would have spent in the cab or in performing his other duties outside the cab. The panel was therefore unable to attribute any specific noise levels to the work the worker performed on a daily basis or to identify continuous exposure for a sufficient length of time as required under the Policy.

The panel is satisfied that the medical information on file shows that there is a pronounced and significant asymmetry in the worker's hearing loss. The worker's hearing loss was demonstrated unilaterally in his left ear in 1995, and it was not until 2015, at least 20 years later, that signs of NIHL were demonstrated in the worker's right ear. The panel notes that this asymmetry in the worker's hearing loss did not change over the years.

The panel further notes that the worker already had a significant hearing loss in his left ear by July 14, 1995, the date of the earliest audiogram on file. Based on our review of the information on file and as presented at the hearing, the panel is unable to account for the worker's left ear hearing loss prior to 1995.

The panel understands that NIHL is typically bilateral and symmetric. Although the worker and his advocate suggested, and provided information supporting, possible explanations for the worker's asymmetrical hearing loss, the panel is not satisfied that these explain the significant differences between the worker's left and right ears.

The worker and his advocate submitted in particular that the cause of the left ear hearing loss was explained by the proximity of his left ear to the open window of the cab of the vehicle. The panel considered this argument, but is not satisfied that the worker's left ear was exposed to significantly greater noise than his right ear. The evidence indicated that the window would have been open in the summer in particular, due to the absence of air conditioning in the vehicle. The panel also considered the worker's positioning in the cab, but cannot attribute the significantly increased exposure that would be necessary for such asymmetrical hearing loss to this factor.

In response to questions from the panel as to particular noises which caused him the most problems, the worker noted that it was the combination of things, but would have included air horns and releasing handbrakes which were particularly loud. The panel notes that the sounds from the air horn or releasing brakes would result in a very temporary exposure of intermittent and short duration, and that there was a lack of data showing what the noise level of those sounds might be or the effect they might have on the noise level in the cab when the window was open or shut.

The panel notes that the worker also relied upon the evidence of an ENT specialist in a First Report dated April 19, 2018. The panel is unable to attach weight to this opinion as it was based on the worker's description of his duties and noise in his workplace, specifically that his left ear sustained greater exposure to noise than his right ear. As noted above, the panel does not accept that the noise exposure in the cab was significantly greater for the worker's left ear than his right ear.

The evidence also shows that the worker wore hearing protection once it became mandatory in 1995, which would have had the general effect of reducing the level of noise to which he was exposed. The worker and his advocate indicated that ear plugs were available prior to that, and the worker stated that he wore them sometimes, but could not say how much, and said it depended mostly on the noise of the particular vehicle, as some units were older.

In conclusion, the panel accepts that the worker worked in a very loud environment. Based on our review of all of the information which is before us, however, the panel is unable to find that the worker's exposure to occupational noise satisfied the criteria under the Policy or that the worker's bilateral or left or right hearing loss was caused or changed because of his job duties.

Based on the foregoing, the panel finds, on a balance of probabilities, that the worker did not suffer a noise-induced hearing loss during the course of his employment due to exposure to levels of noxious noise as set out in the Policy. The worker's claim for noise-induced hearing loss is therefore not acceptable.

The worker's appeal is dismissed.

Panel Members

M. L. Harrison, Presiding Officer
P. Challoner, Commissioner
R. Ripley, Commissioner

Recording Secretary, J. Lee

M. L. Harrison - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 24th day of April, 2020