title: AMTAS(®): automated method for testing auditory sensitivity: III. sensorineural hearing loss and air-bone gaps.
abstract: OBJECTIVE
  The objectives were to measure the occlusion effect produced by three earphones-circumaural, supra-aural, and insert-and to compare air- and bone-conduction thresholds obtained with manual and automated methods for subjects with sensorineural hearing loss.
  
  
  METHODS
  Acoustic and psychoacoustic occlusion effects were measured with each earphone. Manual and automated, air- and bone-conduction thresholds were compared.
  
  
  METHODS
  Occlusion effects were measured for six adult subjects with normal external and middle ears. Pure-tone thresholds were measured for nineteen ears of thirteen subjects with sensorineural hearing loss.
  
  
  RESULTS
  The supra-aural earphone produced the largest occlusion effects, followed by the insert and circumaural earphones. Some systematic differences in air-conduction thresholds were found for the two procedures that may be attributable to earphone differences. A large air-bone gap at 4 kHz, reported in a previous study, was replicated.
  
  
  CONCLUSIONS
  From 0.5 to 8.0 kHz, occlusion effects produced by the circumaural earphone are sufficiently small that covering the ear does not appreciably alter bone-conduction thresholds. Air-conduction threshold differences warrant further study to determine if reference equivalent threshold sound pressure levels for the two earphones produce equivalent thresholds. The large air-bone gap at 4 kHz suggests the possibility of an incorrect reference equivalent threshold force level at that frequency.
authors.affiliation: Department of Otolaryngology, University of Minnesota , Minneapolis, USA. margo001@umn.edu
authors.forename: Robert H
authors.initials: RH
authors.lastname: Margolis
authors.forename: Brian C J
authors.initials: BC
authors.lastname: Moore
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone / Q000295:instrumentation / Q000379:methods*; D001306:Auditory Pathways / Q000503:physiopathology*; D001309:Auditory Threshold; D001331:Automation; D001844:Bone Conduction; D016022:Case-Control Studies; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011571:Psychoacoustics; D055815:Young Adult