title: Extended high-frequency thresholds in college students: effects of music player use and other recreational noise.
abstract: BACKGROUND
  Human hearing is sensitive to sounds from as low as 20 Hz to as high as 20,000 Hz in normal ears. However, clinical tests of human hearing rarely include extended high-frequency (EHF) threshold assessments, at frequencies extending beyond 8000 Hz. EHF thresholds have been suggested for use monitoring the earliest effects of noise on the inner ear, although the clinical usefulness of EHF threshold testing is not well established for this purpose.
  
  
  OBJECTIVE
  The primary objective of this study was to determine if EHF thresholds in healthy, young adult college students vary as a function of recreational noise exposure.
  
  
  METHODS
  A retrospective analysis of a laboratory database was conducted; all participants with both EHF threshold testing and noise history data were included. The potential for "preclinical" EHF deficits was assessed based on the measured thresholds, with the noise surveys used to estimate recreational noise exposure.
  
  
  METHODS
  EHF thresholds measured during participation in other ongoing studies were available from 87 participants (34 male and 53 female); all participants had hearing within normal clinical limits (≤25 HL) at conventional frequencies (0.25-8 kHz).
  
  
  RESULTS
  EHF thresholds closely matched standard reference thresholds [ANSI S3.6 (1996) Annex C]. There were statistically reliable threshold differences in participants who used music players, with 3-6 dB worse thresholds at the highest test frequencies (10-16 kHz) in participants who reported long-term use of music player devices (>5 yr), or higher listening levels during music player use.
  
  
  CONCLUSIONS
  It should be possible to detect small changes in high-frequency hearing for patients or participants who undergo repeated testing at periodic intervals. However, the increased population-level variability in thresholds at the highest frequencies will make it difficult to identify the presence of small but potentially important deficits in otherwise normal-hearing individuals who do not have previously established baseline data.
authors.affiliation: Department of Speech, Language, and Hearing Sciences, University of Florida, Gainesville, FL.
authors.forename: Colleen G
authors.initials: CG
authors.lastname: Le Prell
authors.forename: Christopher
authors.initials: C
authors.lastname: Spankovich
authors.forename: Edward
authors.initials: E
authors.lastname: Lobariñas
authors.forename: Scott K
authors.initials: SK
authors.lastname: Griffiths
mesh_terms: D000293:Adolescent; D000328:Adult; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology*; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000175:diagnosis / Q000503:physiopathology*; D006320:Hearing Tests / Q000295:instrumentation*; D006801:Humans; D008297:Male; D009146:Music; D009622:Noise; D012016:Reference Values; D013334:Students; D055815:Young Adult