Date of Award

Spring 2010

Document Type


Degree Name

Doctor of Audiology (AuD)


School of Communication

First Advisor

Melinda F. Bryan


The present study (1) examined the sound pressure levels (SPLs) of iPod users and nonusers at preferred listening levels measured on Knowles Electronic Manikin for Acoustical Research (KEMAR), and (2) determined if those SPLs exceeded the OSHA standards for acceptable hearing levels. Forty subjects, divided into one of the four following groups participated in this study: (1) inexperienced males, (2) experienced males, (3) inexperienced females, or (4) experienced females. Each participant was asked to set the music stimuli to their preferred listening level while in the presence of background noise, simulating a real world listening environment. SPL values were then measured and averaged from 125 to 8000 Hz for both stimulus (music and white noise) and measurement (linear and A-weighted) scales using KEMAR and a program developed by National Instruments. The results revealed that SPL values were dependent on both stimulus (music or white noise) and measurement scale (linear or A-weighted); however, SPL values were not dependent on gender (male and female) or experience level (inexperienced and experienced). The results further revealed that, on average, SPLs in the ear canal produced by the iPod at a listener's preferred listening level did not exceed the OSHA standards for acceptable sound pressure levels. Nevertheless, listening to music at hazardous noise levels for extended periods of time may be detrimental to hearing sensitivity, thereby causing temporary and/or permanent hearing loss.