title: [Objective audiometry with DPOAEs : New findings for generation mechanisms and clinical applications. German version].
abstract: BACKGROUND
  Distortion product otoacoustic emissions (DPOAEs) and transient evoked otoacoustic emissions (TEOAEs) are sound waves generated as byproducts of the cochlear amplifier. These are measurable in the auditory canal and represent an objective method for diagnosing functional disorders of the inner ear. Conventional DPOAE and TEOAE methods permit detection of hearing impairment, but with less than desirable accuracy.
  
  
  OBJECTIVE
  By accounting for DPOAE generation mechanisms, the aim is to improve the accuracy of inner-ear diagnosis.
  
  
  METHODS
  DPOAEs consist of two components, which emerge at different positions along the cochlea and which may cause artifacts due to mutual interference. Here, the two components are separated in the time domain using short stimulus pulses. Optimized stimulus levels facilitate the acquisition of DPOAEs with maximum amplitudes. DPOAE and Békésy audiograms were recorded from 41 subjects in a clinically relevant frequency range of 1.5 to 6 kHz.
  
  
  RESULTS
  The short stimulus pulses allowed artifact-free measurement of DPOAEs. Semilogarithmic input-output functions yielded estimated distortion product thresholds, which were significantly correlated with the subjectively acquired Békésy thresholds. In addition, they allowed detection of hearing impairment from 20 dB HL, with 95 % sensitivity and only a 5 % false-positive rate. This accuracy was achieved with a measurement time of about 1-2 min per frequency.
  
  
  CONCLUSIONS
  Compared to conventional DPOAE and TEOAE methods, separation of DPOAE components using short-pulse DPOAEs in combination with optimized stimulus parameters considerably enhances the accuracy of DPOAEs for diagnosing impairment of the cochlear amplifier.
authors.affiliation: Sektion für Physiologische Akustik und Kommunikation, Universitäts-HNO-Klinik Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Deutschland.
authors.forename: D
authors.initials: D
authors.lastname: Zelle
authors.affiliation: Sektion für Physiologische Akustik und Kommunikation, Universitäts-HNO-Klinik Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Deutschland.
authors.forename: E
authors.initials: E
authors.lastname: Dalhoff
authors.affiliation: Sektion für Physiologische Akustik und Kommunikation, Universitäts-HNO-Klinik Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Deutschland. anthony.gummer@uni-tuebingen.de.
authors.forename: A W
authors.initials: AW
authors.lastname: Gummer
mesh_terms: D000328:Adult; D000368:Aged; D001300:Audiometry, Evoked Response / Q000379:methods*; D001301:Audiometry, Pure-Tone / Q000379:methods*; D001309:Auditory Threshold; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D034381:Hearing Loss / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017084:Otoacoustic Emissions, Spontaneous; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: Acoustic stimulation; Auditory threshold; Cochlear amplifier; Hearing; Hearing loss