title: Short-term variability of pure-tone thresholds obtained with TDH-39P earphones.
abstract: OBJECTIVE
  To estimate the short-term variability and correlates of variability in pure-tone thresholds obtained using audiometric equipment designed for occupational use, and to examine the justification for excluding 8 kHz as a mandatory threshold in occupational hearing conservation programs.
  
  
  METHODS
  Pure-tone thresholds and other hearing-related tests (e.g. noise dosimetry, otoscopy, middle-ear assessment) were conducted with a group of 527 adults between 20 and 69 years of age. Five measurement visits were completed by participants within 14 days.
  
  
  RESULTS
  The 50% critical difference boundaries were - 5 and 0 dB at 4 kHz and below and - 5 and 5 dB at 6 and 8 kHz. The likelihood of spurious notches due to test-retest variability was substantially lower than the likelihood of failing to detect a notched configuration when present. Correlates of variability included stimulus frequency, baseline threshold, acoustic reflectance of the ear, average noise exposure during the previous eight hours, age, and the tester's level of education in audiology.
  
  
  CONCLUSIONS
  The short-term variability in 8-kHz pure-tone thresholds obtained with the TDH-39P earphone was slightly greater than at other frequencies, but this difference was not large enough to justify the disadvantages stemming from the inability to detect a 6-kHz notch.
authors.affiliation: * Department of Speech Pathology and Audiology, Western Michigan University , Kalamazoo , USA.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Flamme
authors.forename: Mark R
authors.initials: MR
authors.lastname: Stephenson
authors.forename: Kristy K
authors.initials: KK
authors.lastname: Deiters
authors.forename: Amanda
authors.initials: A
authors.lastname: Hessenauer
authors.forename: Devon K
authors.initials: DK
authors.lastname: VanGessel
authors.forename: Kyle
authors.initials: K
authors.lastname: Geda
authors.forename: Krista
authors.initials: K
authors.lastname: Wyllys
authors.forename: Kara D
authors.initials: KD
authors.lastname: McGregor
mesh_terms: D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone / Q000295:instrumentation*; D001309:Auditory Threshold; D004867:Equipment Design; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D009784:Occupational Diseases / Q000175:diagnosis* / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects*; D016272:Occupational Health; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D055815:Young Adult