title: Intra and intersubject variability in auditory steady-state response amplitude with high modulation rates to 1000 Hz amplitude modulated and tone pip stimuli.
abstract: OBJECTIVE
  This study set out to provide further information on how high modulation/stimulus rates affect the auditory steady-state response (ASSR) amplitude for a 1000-Hz tone, and how this effect varies between individuals. Both sinusoidal amplitude modulated tones and tone pip stimuli were investigated.
  
  
  METHODS
  Modulation/stimulus rates were 70, 80, and 90 Hz and the peak to peak stimulus levels were matched for the two different types of stimuli, at 90.5 dBSPLppe.
  
  
  METHODS
  The study was carried out on fourteen normally-hearing adults (9 males and 5 females)
  
  
  RESULTS
  Overall the ASSR amplitude to the two types of stimuli was similar. In general there was an increasing response amplitude between rates of 70 and 90 Hz; The relationship between the amplitude of the response and the modulation /stimulus rate varied considerably between subjects.
  
  
  CONCLUSIONS
  Optimum stimulus rates based on group data may not give the best rate in a significant proportion of subjects. Currently tone pip ABR is the primary method used in assessing hearing in babies. Finding a way of avoiding suboptimal stimulus rates for '80-Hz' ASSR in babies will improve the likelihood of ASSR being seen as an alternative.
authors.affiliation: Hearing Services, Sheffield Children's NHS Foundation Trust, Sheffield, S10 2TH, UK. michelle.foster@sch.nhs.uk
authors.forename: Michelle
authors.initials: M
authors.lastname: Foster
authors.forename: John
authors.initials: J
authors.lastname: Stevens
authors.forename: Siobhan
authors.initials: S
authors.lastname: Brennan
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001301:Audiometry, Pure-Tone; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception; D001309:Auditory Threshold; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D055815:Young Adult