title: Young adults' use and output level settings of personal music systems.
abstract: OBJECTIVE
  There are growing concerns over noise exposure via personal music system use by young adults. One purpose of this study was to evaluate the prevalence of personal music system use and the listening patterns associated with these systems in a large sample of young adults. A second purpose of this study was to measure the dB SPL in the ear canal of young adults while they blindly set the volume of a personal music system to four settings.
  
  
  METHODS
  In the first study, the personal music system use survey was completed by 1016 students at various locations on the San Diego State University campus. Questions included sex, age, ethnicity, race, and whether or not they used a personal music system. Students who answered Yes to using a personal music system were instructed to complete the remaining 11 closed-set questions. These questions dealt with type of earphones used with the system, most common listening environment, length of time per day the system was used, and the volume setting. The differences between women and men and across ethnicity and race were evaluated for the questions. In the second study, a probe microphone placed in the ear canal of 32 participants was used to determine the dB SPL of four loudness categories at which the participants blindly set the level of a personal music system: low, medium or comfortable, loud, and very loud.
  
  
  RESULTS
  In study 1, over 90% of the participants who completed the survey reported using a personal music system. Over 50% of those who use a personal music system reported listening between 1 and 3 hrs and almost 90% reported listening at either a medium or loud volume. Men were significantly more likely to report listening to their system for a longer duration compared with women and more likely to report listening at a very loud volume. There was a trend for Hispanic or Latino students to report listening for longer durations compared with Not Hispanic or Latino students, but this difference was not statistically significant. Black or African American students were significantly more likely to report listening to their personal music system between 3 and 5 hrs and more than 5 hrs and to report listening at a very loud volume compared with other racial groups. In study 2, the mean dB SPL values for low, medium or comfortable, loud, and very loud were 62.0, 71.6, 87.7, and 97.8 dB SPL, respectively. Men set the level of very loud significantly higher than women.
  
  
  CONCLUSIONS
  It is clear that a vast majority of young adults who completed the personal music system use survey listen to a system using earphones. Most of the respondents listen between 1 and 3 hrs a day at a medium or loud volume. Based on the probe microphone measurement results, the volume settings for reported durations may not be hazardous for hearing. Long-term use of personal music systems, however, in combination with other noise exposures (i.e., recreational, occupational), and their effect on hearing remains a question for additional research.
authors.affiliation: School of Speech, Language, and Hearing Sciences, SDSU/UCSD Joint Doctoral Program in Audiology, San Diego State University, San Diego, California 92182-1518, USA. ptorre@mail.sdsu.edu
authors.forename: Peter
authors.initials: P
authors.lastname: Torre
mesh_terms: D000293:Adolescent; D003625:Data Collection; D004424:Ear Canal; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000208:ethnology*; D006801:Humans; D007899:Leisure Activities; D008144:Loudness Perception; D008297:Male; D009146:Music; D015995:Prevalence; D017678:Sex Distribution; D013334:Students / Q000706:statistics & numerical data; D055815:Young Adult