10/5/98 Lecture: Evidence for Hearing Loss?

News Flash: Judge Awards U2 Fan $34,000 Over Hearing Loss: French concert promoter must pay man who claims he's legally deaf from 1993 show.

and A Statement from the Better Hearing Institute:

"(Washington, D.C.) With candor and confidence, President Bill Clinton has chosen to wear hearing aids to treat the high-frequency hearing loss that has challenged him over the last years. During his routine annual physical examination, the President was fitted with completely in-the-canal hearing aids which will eliminate the difficulties he has experienced in crowded and noisy environments. His type of hearing loss is not uncommon for "baby boomers" whose lives have been punctuated by the loud noises of rock and roll music and crowds." (emphasis added by Prof. Lew)

Noise Levels associated with Urban Living (all numbers are Decibels)

0 Threshold of normal hearing

20 Whispered voice

40 Refrigerator humming

60 Normal conversation

80 City traffic noise

90 Lawn mower, Motorcycle

100 Wood shop

110 Chainsaw

120 Boom cars, Snowmobile

140 Rock concerts, Firecrackers, Gunshot, Jet Engine

According to the U.S. Public Health Service (PHS, 1991), some 10 million of the estimated 21 million Americans with hearing impairments owe their losses to noise exposure. The study goes on to say that it is unclear whether the incidence of hearing impairment has risen in recent years because the necessary studies have not been conducted.

Summaries of some hearing studies:

1. Rintelmann, Borus, Johnson & Smitely (1968 & 1975) tested 42 professional rock musicians between the ages of 16-23 who were being exposed to at least 105db for more than 10 hours/week for nearly 3 years. About 5% showed any symptom of hearing loss. Four years later, they retested 10 of the musicians who were still actively playing and found that their hearing had not changed.

The authors also tested 120 college students (average age 20 years) and divided them into two groups -- those who listened to music for at least two hours per week and those who listened to music less than 2 hours per week (the actual averages were 5 hours per week for the first group and 41 minutes per week for the second).

Their study showed that 5 persons had hearing loss. All 5 were in the group who listened to music LESS than 2 hours per week.

2. National Institute for Occupational Safety and Health (1972) Did a study where 400 persons served as "controls", 100 others were professional rock musicians, and 100 others were people who attended rock concerts regularly (i.e. 2-3 concerts a month). All the controls, musicians and concert goers were between the ages of 18-21. No differences were noticed between the groups when their hearing was tested.

3. Barry & Thomas (1974) Subjected 10 volunteer students to 60 minutes of exposure to loud rock music and 60 minutes of exposure to industrial noise at similar sound levels (90 db) and measured hearing ability after each exposure. The results showed that temporary hearing loss was greater after exposure to industrial noise than to music.