title: Stimulus and transducer effects on threshold.
abstract: OBJECTIVE
  This study examined differences in thresholds obtained under Sennheiser HDA200 circumaural earphones using pure tone, equivalent rectangular noise bands, and 1/3 octave noise bands relative to thresholds obtained using Telephonics TDH-39P supra-aural earphones.
  
  
  METHODS
  Thresholds were obtained via each transducer and stimulus condition six times within a 10-day period.
  
  
  METHODS
  Forty-nine adults were selected from a prior study to represent low, moderate, and high threshold reliability.
  
  
  RESULTS
  The results suggested that (1) only small adjustments were needed to reach equivalent TDH-39P thresholds, (2) pure-tone thresholds obtained with HDA200 circumaural earphones had reliability equal to or better than those obtained using TDH-39P earphones, (3) the reliability of noise-band thresholds improved with broader stimulus bandwidth and was either equal to or better than pure-tone thresholds, and (4) frequency-specificity declined with stimulus bandwidths greater than one equivalent rectangular band, which could complicate early detection of hearing changes that occur within a narrow frequency range.
  
  
  CONCLUSIONS
  These data suggest that circumaural earphones such as the HDA200 headphones provide better reliability for audiometric testing as compared to the TDH-39P earphones. These data support the use of noise bands, preferably ERB noises, as stimuli for audiometric monitoring.
authors.affiliation: * Department of Speech Pathology and Audiology, Western Michigan University , Kalamazoo, Michigan , USA.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Flamme
authors.forename: Kyle
authors.initials: K
authors.lastname: Geda
authors.forename: Kara D
authors.initials: KD
authors.lastname: McGregor
authors.forename: Krista
authors.initials: K
authors.lastname: Wyllys
authors.forename: Kristy K
authors.initials: KK
authors.lastname: Deiters
authors.forename: William J
authors.initials: WJ
authors.lastname: Murphy
authors.forename: Mark R
authors.initials: MR
authors.lastname: Stephenson
mesh_terms: D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone / Q000295:instrumentation*; D001309:Auditory Threshold; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: Audiometry; noise-induced hearing loss; occupational health; reliability