Listening habits of iPod users.
OBJECTIVE
To estimate real-environment iPod listening levels for listeners in 4 environments to gain insight into whether average listeners receive dosages exceeding occupational noise exposure guidelines as a result of their listening habits.


METHODS
The earbud outputs of iPods were connected directly into the inputs of a digital recorder to make recordings of listening levels. These recordings were used to estimate listening levels using reference recordings made in a real ear. Recordings were made in 4 environments with a wide range of background noises: (a) a library, (b) a student center, (c) busy streets, and (d) the subway.


RESULTS
None of the 64 listeners were estimated to exceed allowable occupational dosages, with a maximum dose of 7.57% based on Occupational Safety and Health Administration (OSHA; 1998) methods and 10.83% based on National Institute for Occupational Safety and Health (NIOSH; 1998) methods.


CONCLUSIONS
All of the listeners surveyed were exposed to dosages well below OSHA and NIOSH occupational regulations. Although this does not guarantee individual safety, the results do not support the widespread concern regarding the safety of common iPod usage. However, measurements made in this study agree with the finding that iPod output can exceed safe levels and further support recommendations to monitor and limit listening volume and listening duration.
Epstein
Michael
M
Northeastern University, Boston, MA 02115, USA. m.epstein@neu.edu
Marozeau
Jeremy
J
Cleveland
Sandra
S
D000161:Acoustic Stimulation / Q000379:methods; D001301:Audiometry, Pure-Tone; D004424:Ear Canal; D005260:Female; D006309:Hearing; D006317:Hearing Loss, Noise-Induced / Q000517:prevention & control*; D006801:Humans; D008144:Loudness Perception; D055539:MP3-Player; D008297:Male; D009146:Music; D009622:Noise / Q000009:adverse effects*; D014432:Tympanic Membrane; D014481:United States; D014489:United States Occupational Safety and Health Administration