title: Auditory steady state responses in normal-hearing and hearing-impaired adults: an analysis of between-session amplitude and latency repeatability, test time, and F ratio detection paradigms.
abstract: OBJECTIVE
  The aim of this study was to assess the between-session repeatability of auditory steady state response (ASSR) amplitudes and to examine F ratio response detection parameters.
  
  
  METHODS
  Suprathreshold ASSRs were recorded from 20 normal-hearing and 10 hearing-impaired subjects. Amplitudes and latencies were recorded in two test sessions conducted on separate days.
  
  
  METHODS
  The repeatability coefficients (limits of expected variation in repeat measurements) for amplitude and latency of ASSRs were calculated. The test time required for the responses to reach significance at 1%, 2%, and 5% F ratios was analyzed. The percentage false response detection rate was calculated to determine the suitability of current ASSR threshold estimation protocols for use in audiology clinics.
  
  
  RESULTS
  The repeatability coefficients for the amplitude of ASSRs were 29 nV for the normal-hearing subjects and 57 nV for the hearing-impaired subjects. The repeatability coefficients for the latency of ASSR were 1.10 msec for the normal-hearing subjects and 1.19 msec for the hearing-impaired subjects. High false-positive detection rates were found for detection procedures that used variable test time ("stop when significance reached" methods).
  
  
  CONCLUSIONS
  The results of this study showed that ASSR amplitudes are highly variable between test sessions with an average estimated variability in response amplitude of ± 40% for normal-hearing participants and ± 97% for hearing-impaired participants. This could be a possible cause of test-retest differences in ASSR threshold measurements, as it could potentially lead to thresholds that were above the EEG noise level and significant in one test session subsequently falling below the EEG noise level in the repeat test session leading to insignificant response and thus poorer ASSR threshold.
authors: Audiology and Deafness Research Group, School of Psychological Sciences, The University of Manchester, Manchester, United Kingdom. timothy.wilding@manchester.ac.uk
authors: Timothy S
authors: TS
authors: Wilding
authors: Colette M
authors: CM
authors: McKay
authors: Richard J
authors: RJ
authors: Baker
authors: Karolina
authors: K
authors: Kluk
mesh_terms: D000293:Adolescent; D000368:Aged; D001300:Audiometry, Evoked Response / Q000379:methods* / Q000592:standards*; D001307:Auditory Perception / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology; D004569:Electroencephalography / Q000379:methods / Q000592:standards; D005072:Evoked Potentials, Auditory; D005189:False Positive Reactions; D005260:Female; D006311:Hearing Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology; D015203:Reproducibility of Results; D055815:Young Adult