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 for noise induced hearing loss was not acceptable. A hearing was held on February 16, 2016 to consider the worker's appeal.

Issue

Whether or not the claim is acceptable.

Decision

That the claim is acceptable

Decision: Unanimous

Background

The worker filed a "Worker's Claim for Hearing Loss" form with the WCB on October 3, 2014. The worker stated that his hearing loss came on gradually and that he was exposed to occasional noise in the workplace. Regarding his employment history, the worker reported that he worked as a machinist for two specific employers between 1976 and the present. Between 1976 and 1979, the equipment he used included a lathe, milling machine, drill press, etc. His exposure to noise was occasional and he wore his own hearing protection. Between 1979 and the present, his exposure to noise as a machinist included working with lathes, drill presses and train engines. He wore hearing protection at all times with this employer.

File records show that the WCB gathered additional information from the worker regarding his hearing loss difficulties and the work he performed in various positions and shops during his employment career. The WCB also contacted both employers identified by the worker to confirm his noise exposure. Copies of audiogram test results were obtained and were reviewed by a WCB ear, nose and throat ("ENT") consultant.

On December 11, 2014, the WCB advised the worker that his claim for compensation was not accepted. The worker was advised that decibel readings with his second employer confirmed that the average noise levels were as follows:

• 93.83 decibels in the diesel/back shop;

• 71.5 to 79.57 decibels in the electric shop;

• 93.83 decibels in the load test shop;

• from 2011 to the present the noise levels were 82.91 to 84.91 decibels in the air brake shop.

The decision stated that hearing test results from 1985 to 2014 were obtained and reviewed by the WCB ENT consultant. The worker had normal hearing up to and including January 1994. A hearing test completed in September of 1994 noted noise induced hearing loss in his right ear only. In 2012, the testing revealed bilateral noise induced hearing loss.

The first evidence of bilateral noise induced hearing loss was in 2012 and the worker was wearing suitable hearing protection consistently when exposed to noise. As hearing protection was worn when exposed to noise, the noise levels in the WCB's opinion would have been reduced below 85 decibels. As such, the WCB was unable to determine that the worker's hearing loss was a result of noise exposure at work.

On May 4, 2015, the worker's union representative wrote Review Office to appeal the WCB's decision to deny the claim. A copy of the submission was provided to the employer and the employer's response was provided to the union representative for final comment.

On July 17, 2015, Review Office stated that it was unable to find that the worker suffered a noise induced hearing loss ("NIHL") as a result of noxious noise exposure while working in Manitoba. Review Office commented that the noise level surveys provided by the employer and the worker's representative showed that at times, the worker worked in areas where the noise was 85 decibels or greater. The employer indicated that hearing protection had been available since 1970. The worker stated that hearing protection was always provided. When wearing hearing protection, the worker's noise exposure would have been at levels below 85 decibels.

Review Office stated that the 1994 screening audiogram showed noise induced hearing loss in the right ear only. It was noted that NIHL is normally symmetrical and develops slowly after many years of exposure and presents as a gradual, symmetrical decline in hearing. The evidence on file did not support an occupational cause for the worker's asymmetrical hearing loss and Review Office could not account for why the worker's hearing in his left ear would be normal up to 2012 if exposed to the same noise in his right ear.

On August 25, 2015, the worker's union representative appealed Review Office's decision to the Appeal Commission and an oral hearing was held on February 16, 2016.

Following the hearing, the appeal panel met to discuss the case and requested additional data from the employer regarding hearing protection used by the worker between 1982 and the present, and noise exposure data from the air brake shop and load test areas. On March 11, 2016, the worker was provided with a copy of the information submitted by the employer and was asked to provide comment. On March 30, 2016, the panel met further to discuss the case and rendered its decision on the issue under appeal.

Reasons

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.

Subsection 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 to the worker by the WCB.

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. With respect to a workplace event, the Policy states:

Hearing-loss claims that are the result of trauma or a single exposure to occupational noise are adjudicated in the same manner as other workplace injuries…

With respect to prolonged exposure to excessive noise, the Policy notes that not all hearing loss is caused by exposure to noise at work, and states:

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 represented by a union representative, who made a presentation on the worker's behalf. The worker responded to questions from the panel.

The worker's representative stated that it was their position that the worker's hearing loss is compensable. The worker, a retired heavy duty mechanic/machinist, worked for the employer for 35 years in what was referred to in the notice of appeal as "one of the most noise noxious working environments."

The worker's representative submitted that everywhere the worker worked over the course of his 35 years, the noise levels were well above 84 decibels, the federal limit which generally applied to that undertaking. He briefly described the various areas where the worker had worked, referring to the dates he worked in each area, the type of work involved and equipment used, and decibel ratings for the area. He noted that the decibel ratings were from testing done by the employer's occupational health department in conjunction with an outside firm, where they had just walked around the various shops with a dosimeter and taken noise levels.

The representative referred to the load test area in particular, where the worker worked from 1995 to 2000, saying that this was probably the loudest and noisiest shop. In that area, they would put a new engine into a locomotive and start it inside the building at an idle, run it for a while, then take it outside and run it for up to eight hours or more at the eighth notch or basically wide open. While the engine was running at open throttle, the worker would be inside the actual long nose, being the cab that goes over the hood which is over the engine on the long side of the locomotive. There would be a series of doors down the side of the locomotive, and the worker would have to go inside the compartment with the engine running at full throttle to torque the engine. He would also be checking for leaks and checking all the components, as well as making sure that the engine was running at the proper RPM. This would expose the worker to a great deal of noise.

The representative said that he had located and previously submitted a separate report for this area which indicated that the average noise level that a machinist would be exposed to for a 6.5 hour day, being the length of time that the locomotive was outside the shop, was 108.7 decibels with peaks inside the long nose or the hood, while the machinist was standing beside the engine, of 141 decibels. He noted that the testing which identified those levels was done by the employer's occupational health services, with a machinist wearing a dosimeter around his neck and performing the same normal daily duties as the worker would have done on a daily basis.

The worker's representative indicated that he had questioned the employer's sound level submissions, which he believed were low. He had asked for the analytical statistics, the methodology, and copies of the tests used to arrive at the readings provided, given that the employer had not indicated when and under what conditions those tests were done, but none of that information had been provided. In his submission, the information which the employer said was provided to the WCB as a baseline was not really an appropriate measure.

The worker's representative said that the worker had tried to protect his hearing and limit any damage by wearing his personal hearing protection right from the start. He noted that apart from the occasional use of power tools to do home repairs, there were really no outside activities which might have caused the worker's NIHL.

Employer's Position

The employer was represented by its Workers' Compensation Officer. The employer's representative advised that the employer agreed with the Review Office decision that the claim is not acceptable.

The employer's representative noted that the claim was initially denied based in part on an inability to provide an occupational reason to explain the asymmetrical hearing loss. He said that it was not until 2012 that the first evidence of bilateral hearing loss was identified. He submitted that it was also important to note that the WCB ENT consultant reviewed the file in November 2014 and suggested that the results were still asymmetric in nature, and that a hearing aid would not be required for the worker's left ear.

The employer's representative also stated that the worker has advised that he consistently used hearing protection since approximately 1982, and submitted that this would have reduced his noise exposure to below noxious levels, based on the dosimeter results which the WCB has on file from the employer.

It was submitted that while the worker's representative questioned the validity of the audio results provided to WCB, the reports that the worker's representative had provided would not be considered an accurate representation of average noise exposure over time. In particular, the July 2, 1992 report specifically stated that the readings were very high maximum noise levels, and that high exposure was only for a very brief period of time. The readings from that shift were also a worst case scenario, in that all shifts would not be dealing with the maximum noise levels. Those readings would therefore not be suitable in determining average exposure.

Referring to an assertion by the worker's representative that the employment has a history of causing permanent hearing loss based on prior claims that the WCB has accepted for other workers, the employer's representative stated that while the employer could appreciate that the WCB has accepted such claims for NIHL at its workplace, it was important to note that each claim is evaluated on its own merits and on the information on file, without precedent. In deciding that the claim was not acceptable, Review Office stated that although the worker would at times have been exposed to noise in excess of 85 decibels, the use of hearing protection would have reduced his exposure to suitable levels. Review Office also placed significant weight on the fact that NIHL is normally symmetrical and that no occupational cause for the worker's hearing loss could be identified.

The employer's representative stated that it was important to note that if the claim was evaluated based on the level of hearing loss experienced in the left ear only, assuming that there was an occupational reason to cause bilateral hearing loss, there would not be sufficient hearing loss to merit the usage of hearing aids according to the WCB medical advisor. He submitted that as such, it could be assumed that the additional hearing loss in the right ear is due to a non-occupational reason.

Analysis

The issue on this appeal is whether or not the claim is acceptable. 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 that during the course of his employment with the accident employer, the worker sustained NIHL due to exposure to levels of noxious noise as set out in the Policy. The panel is able to make that finding.

The criteria under the Policy provide that the 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 the evidence, the panel is satisfied that this noise threshold has been met in this case.

It is the panel's understanding that the configuration of the test results as shown on the worker's 2014 audiogram and as reflected on the recorded results for the 2012 audiogram are consistent with NIHL in both ears.

The panel places great weight on the opinion of the WCB ENT consultant who reviewed the worker's hearing tests and determined that the worker had noise induced hearing loss, the signs of which were in both ears. While the consultant reported that the date of the first audiogram indicating signs of NIHL in both ears was 2012, the panel notes that the information on file shows that there were large gaps in testing, with the closest previous test having been more than 11 years earlier, in 2001. The panel notes that the WCB ENT consultant's final comment that based on the 2014 audiogram, "a hearing aid is not needed for the left ear at this time" is not inconsistent with his conclusion that the worker has NIHL in both ears.

In all of the circumstances, the panel accepts and adopts the WCB ENT consultant's opinion that the worker has bilateral NIHL.

The panel went on to consider whether the worker's NIHL was related to his employment. At the hearing, the panel spent a considerable amount of time with the worker reviewing his job duties in the different areas he worked in over the course of his employment. The worker's representative and the worker referred to three areas in particular as being extremely noisy, one of which was the load test area where, as indicated above, they tested new engines installed in locomotives. The worker provided further details as to his duties in that area. He stated that they would start the engine inside the building and let it idle for 30 minutes, then move it to the outside area where they would steadily increase the speed every half hour until it reached the eighth notch or full throttle. They would run the engine at full throttle for four or more hours. The worker stated that once the locomotive was outside, he would have to keep testing it, which included entering under the hood to check the oil and water and see that everything was okay. He said that he would have to check the readings under the hood every 10 to 15 minutes, and it would take him about 10 minutes to look at the gauges. As it was very hot, he would work as quickly as possible, then go to the cab for a little bit to cool off. He also spoke of putting a "gauge in each piston" at the eighth notch, during which time he would "have to stay at least an hour inside…"

The worker stated that he worked the evening shift in the load test area, from 4:00 to 12:00, and that there was no difference in the work load or exposure between the day and evening shifts. He would not be testing every day, but perhaps every 2 or 3 days. On the days when he was not testing, he would be doing repairs in the shop, which was noisy too. There was still noise from outside where others were running the engines. There were 3 units in the load test area, and there could be 2 or 3 engines running outside at eighth notch while he was working inside. The locomotives were very close to the shop, and even with the door closed, it was very noisy and they still had to use earmuffs. The panel notes that while the information on file indicated that the worker was employed in the load test area from 1995 to 2000, the employer's representative's information at the hearing was that he worked in that area for 7 years, up until 2002.

With respect to the level of noise in the load test area, the file information originally identified average noise levels at 93.83 decibels, which was the exact same number as was listed for the diesel/back shop. At the hearing, the employer representative said that he could not comment as to why the numbers were the same without seeing the report they came from. Information which the employer's representative provided on March 10, 2016 in response to a request from the panel, included a document from 1980 that referred to a sound level reading at the "Diesel Test" location of 93.83, which indicated that it was based on 6 readings, with only one unit in the Test building. In his letter of March 10, 2016, the employer's representative further stated that based on the information he had provided, it could be assumed that the exposure while employed at the load test would likely average somewhere between 94 and 98 decibels.

Having carefully considered all of the evidence, the panel attaches more weight to the information contained in the July 2, 1992 letter on file, where the average noise levels for 6.5 hours in respect of the work performed by a machinist in the load test area are listed as being 108.7 decibels and the maximum noise levels as over 141 decibels. The panel is satisfied that these levels are more consistent with the evidence as to what the worker would have done in that area. The panel also notes that the letter is more current than the 1980 document which the employer relied on, and indicates that the testing was completed using a dosimeter worn by a machinist during his shift, performing the same duties as the worker would have been doing in that area.

With respect to hearing protection and the effect it might have, the panel notes that there was no question that the worker used hearing protection throughout his career. After the hearing, the panel asked the employer to inquire into what hearing protection would have been used during this period of time. In his response dated March 10, 2016, the employer's representative referred to 1994 documentation which indicated that the worker was then using a particular type of muffs with a Noise Reduction Rating ("NRR") of 27 while working in the load test area, and plugs with an NRR of 29 while working in the air brake shop. The representative noted that they had no other documentation specific to the worker with respect to the hearing protection the worker would have worn. He submitted that the NRR of 27, derated by 25% or 7 decibels to account for actual fit, would be expected to provide a reduction in the noise level of 20 decibels, reducing the worker's exposure to between 74 and 78 decibels when performing load tests.

The panel notes that other documentation provided by the employer on March 10, 2016 referred to a different and "widely used" derating formula which would result in the expected protection level being reduced to 10 decibels (i.e. (NRR-7) ÷2). The panel further understands that a general rule of thumb which is often used in considering the expected reduction in noise level due to hearing protection is to derate the NRR by half, or in this instance 13.5 decibels (50% of an NRR of 27). The panel finds that this derating is more consistent with the suggested 10 decibel abatement than the 25% suggested by the employer. In terms of derating, the panel places more weight on the reduction to 10 or 13.5 decibels for hearing protection.

With respect to the effect of the hearing protection, the panel is satisfied, on a balance of probabilities, that even with that protection, the worker would have been exposed to average levels of noxious noise in excess of 90 decibels on a daily basis in the load test area alone. Given the length of time that the worker was employed in that area and the level of noise exposure on a daily basis, the panel is satisfied that the noise threshold under the Policy has been met.

Accordingly, the panel finds, on a balance of probabilities, that the worker sustained a NIHL during the course of his employment due to exposure to levels of noxious noise within the WCB Policy requirements, and that his claim for hearing loss is acceptable.

The worker's appeal is allowed.

Panel Members

M. L. Harrison, Presiding Officer
A. Finkel, Commissioner
M. Kernaghan, Commissioner

Recording Secretary, B. Kosc

M. L. Harrison - Presiding Officer

Signed at Winnipeg this 19th day of May, 2016