title: False air-bone gaps at 4 kHz in listeners with normal hearing and sensorineural hearing loss.
abstract: OBJECTIVE
  This report presents data from four studies to examine standard bone-conduction reference equivalent threshold force levels (RETFL), especially at 4 kHz where anomalous air-bone gaps are common.
  
  
  METHODS
  Data were mined from studies that obtained air- and bone-conduction thresholds from normal-hearing and sensorineural hearing loss (SNHL) participants, using commercial audiometers and standard audiometric transducers.
  
  
  METHODS
  There were 249 normal-hearing and 188 SNHL participants.
  
  
  RESULTS
  (1) Normal-hearing participants had small air-bone gaps at 0.5, 1.0, and 2.0 kHz (-1.7 to 0.3 dB) and larger air-bone gaps at 4 kHz (10.6 dB). (2) SNHL participants had small air-bone gaps at 0.5, 1.0, and 2.0 kHz (-0.7 to 1.7 dB) and a larger air-bone gap at 4 kHz (14.1 dB). (3) The 4-kHz air-bone gap grew with air-conduction threshold from 10.1 dB when the air-conduction threshold was 5-10 dB HL to 21.1 dB when the air-conduction threshold was greater than 60 dB. (4) With the 4-kHz RETFL corrected by the average SNHL air-bone gap, the relationship between RETFL and frequency is linear with a slope of - 12 dB per octave.
  
  
  CONCLUSIONS
  The 4-kHz air-bone gaps for listeners with SNHL could be avoided by adjusting the 4-kHz RETFL by - 14.1 dB.
authors.affiliation: Department of Otolaryngology, University of Minnesota, Minneapolis, MN 55455, USA. margo001@umn.edu
authors.forename: Robert H
authors.initials: RH
authors.lastname: Margolis
authors.forename: Robert H
authors.initials: RH
authors.lastname: Eikelboom
authors.forename: Chad
authors.initials: C
authors.lastname: Johnson
authors.forename: Samantha M
authors.initials: SM
authors.lastname: Ginter
authors.forename: De Wet
authors.initials: de W
authors.lastname: Swanepoel
authors.forename: Brian C J
authors.initials: BC
authors.lastname: Moore
mesh_terms: D000161:Acoustic Stimulation; D001299:Audiometry; D001309:Auditory Threshold; D001844:Bone Conduction; D016022:Case-Control Studies; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology* / Q000523:psychology; D006801:Humans