Highlights of Noteworthy Decisions

Decision 148 21
K. Jacques
  • Hearing loss
  • Medical opinion (hearing loss) (testing procedures)
  • Medical report (Tribunal medical discussion paper)

The worker appealed a decision of the Appeals Resolution Officer denying entitlement for noise-induced hearing loss.

The worker's audiogram indicated hearing loss of 31 decibels in the right ear but only 19.75 decibels in the left ear, which was insufficient for entitlement under Board policy. The results relied on by the Board were based on bone conduction values. Using air conduction values, the worker had hearing loss of 37.25 decibels in the left ear and 28.5 decibels in the right ear.
According to the Tribunal medical discussion paper on Hearing Loss and Tinnitus, air conduction determines the severity of hearing loss, and bone conduction determines the inner ear portion of hearing loss. Air conduction and bone conduction should be the same for sensorineural hearing loss. If air conduction values are greater than bone conduction values, this usually implies a conductive component to hearing loss. When an asymmetric sensorineural hearing loss exists, steps often need to be taken to exclude pathologic causes.
The Vice-Chair accepted that, although noise-induced hearing loss is generally symmetrical, the existence of a minor asymmetry is insufficient, in itself, to conclusively determine that pathological causes are the reason for an asymmetry. It is possible the asymmetry may be due to one ear receiving greater noise exposure than the other. In this case, there was nothing to suggest an alternative pathological cause of the asymmetry.
The gaps between air conduction and bone conduction values was evidence that the worker's hearing loss included a conductive element. The discussion paper states that, when there is any conductive component to the hearing loss, the calculation should be done using bone conduction values.
Decision No. 1059/15 found a difference of 10 decibels or less was not, in itself, significant and, further, that when there was an insignificant difference between air conduction and bone conduction values combined with a lack of express medical evidence suggesting a conductive reason for the hearing loss, it was appropriate to utilize the air conduction values. However, the Vice-Chair noted that, in Decision No. 1059/15, only two of eight measurements demonstrated a gap whereas, in this case, eight of 10 measurements had a gap. The Vice-Chair was not convinced that having a small gap in the majority of the measurements should be characterized as insignificant.
Given that the worker had mixed hearing loss, it was appropriate to use bone conduction values. Therefore, the worker's hearing loss did not meet the Board policy threshold of 22.5 dB or greater in both ears. The appeal was dismissed.