title: Further comparisons of ABR response amplitudes, test time, and estimation of hearing threshold using frequency-specific chirp and tone pip stimuli in newborns: Findings at 0.5 and 2 kHz.
abstract: OBJECTIVE
  To compare auditory brainstem response (ABR) amplitudes evoked by 0.5 and 2 kHz tone pip and narrowband chirp (NB CE-Chirp) stimuli when testing post-screening newborns. To determine the difference in 'estimated hearing level' correction values.
  
  
  METHODS
  Tests were performed with tone pips and NB CE-Chirps at 0.5 or 2 kHz and the ABR threshold for each stimulus defined. Response amplitude, response quality (Fmp), and residual noise were compared for both stimuli.
  
  
  METHODS
  Thirty-nine babies (42 ears) who passed our ABR discharge criterion at 4 kHz following referral from their newborn hearing screen.
  
  
  RESULTS
  NB CE-Chirp responses were, on average, 31% larger than the tone pip responses at 0.5 kHz and were 52% larger at 2 kHz. Fmp was significantly higher for NB CE-Chirps.
  
  
  CONCLUSIONS
  The advantages of NB CE-Chirps over tone pips we previously identified at 4 and 1 kHz extends to 0.5 and 2 kHz, which supports the use of NB CE-Chirps when testing newborns. We propose that ABR nHL threshold to eHL corrections for NB CE-Chirps should be approximately 5 dB less than corrections for tone pips at 0.5 and 2 kHz, mirroring our recommendation at 4 and 1 kHz.
authors.affiliation: a * Audiology Department, Hearing Centre , Croydon University Hospital , Croydon , UK.
authors.forename: Inga
authors.initials: I
authors.lastname: Ferm
authors.affiliation: b ERA Training & Consultancy Ltd , UK.
authors.forename: Guy
authors.initials: G
authors.lastname: Lightfoot
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000162:Acoustics; D001306:Auditory Pathways / Q000502:physiology*; D001309:Auditory Threshold; D016057:Evoked Potentials, Auditory, Brain Stem; D006309:Hearing; D006801:Humans; D007231:Infant, Newborn; D015997:Neonatal Screening / Q000379:methods*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013997:Time Factors
keywords: Auditory brainstem response; test time; tone pip; narrowband chirp; neural synchrony; amplitude; Fmp; corrections