- © 2007 Canadian Medical Association or its licensors
In a recent CMAJ article, William Hodgetts and Richard Liu examined the risk of hearing loss to people who attended the 2006 Stanley Cup finals in Edmonton.1 The average noise levels during the 3 games were between 100.7 and 104.1 dB with occasional peaks exceeding 120 dB. Audiometric tests showed a temporal threshold shift of up to 20 dB in 1 ear for 1 subject and of 5–10 dB for the second subject.
Any paper dealing with the risk of hearing loss from nonoccupational activities involving high noise levels is welcome, because there is a widespread misconception that only workplace noise exposure can be dangerous. In this regard, the authors must be commended. However, caution has to be taken when interpreting the results of the study. The universally accepted limit of exposure to an A-weighted noise level of 85 dB A for 8 hours, which is cited in the CMAJ article,1 is meant for situations where the exposure occurs for many years. In its ISO 1999 standard, the International Organization for Standardization specifies a method to predict hearing loss for exposures for different lengths of time, always measured in terms of years, not hours.2
A 3-h exposure to the sound levels measured by Hodgetts and Liu will not harm a person if this exposure is not repeated day after day for many years. However, there is definitely value in recommending the use of hearing protectors even if only for the sake of comfort and ease of communication.