title: Prediction of frequency-specific hearing threshold using chirp auditory brainstem response in infants with hearing losses.
abstract: OBJECTIVE
  To investigate the clinical usefulness of the LS-chirp auditory brainstem response for estimation of behavioral thresholds in young children with mild to severe hearing losses.
  
  
  METHODS
  68 infants (136 ears) aged 6-12 months (mean age=9.2 months) with bilateral mild to severe hearing losses were studied at Children's Hospital of Fudan University. In all cases, the children were referred for LS-chirp ABR and visual reinforcement audiometric (VRA) measurements. The low-frequency band chirp (LF-chirp) thresholds (frequency band=0.1-0.85kHz) were compared to the average VRA thresholds (frequency band=0.25-0.5kHz), whereas the high-frequency band chirp (HF-chirp) thresholds (frequency band=1-10kHz) were compared to the average VRA thresholds (frequency band=1-4kHz) using statistical correlation coefficient values.
  
  
  RESULTS
  The LS-chirp ABR thresholds are very close to behavioral hearing levels. The mean differences between chirp-ABR and VRA thresholds were within 5dBHL for all measurements. The smallest mean threshold difference (<3dBHL) was obtained for the severe hearing loss group. The correlation coefficient values (r) were 0.97 at low-frequency and high-frequency bands. For each carrier frequency, the best correlations between chirp-ABR thresholds and VRA thresholds were obtained at VRA frequency of 0.25kHz/LF-chirp (r=0.98) and VRA frequency of 1kHz/HF-chirp (r=0.98).
  
  
  CONCLUSIONS
  This study demonstrates the effectiveness using chirp-ABR predicted frequency-specific thresholds, especially of low and middle frequencies. LS-chirp ABR thresholds determined behavioral thresholds in patients with severe hearing losses were better than for mild hearing losses. The use of a chirp-ABR testing ensures higher sensitivity and accuracy than that of auditory stead-state evoked response (ASSR) for measuring frequency-specific thresholds in young children.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Children's Hospital of Fudan University, 399 Wan Yuan Road, Shanghai 201102, PR China. Electronic address: xuzhengmin@sh163.net.
authors.forename: Zheng-min
authors.initials: ZM
authors.lastname: Xu
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Children's Hospital of Fudan University, 399 Wan Yuan Road, Shanghai 201102, PR China.
authors.forename: Wen-xia
authors.initials: WX
authors.lastname: Cheng
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Children's Hospital of Fudan University, 399 Wan Yuan Road, Shanghai 201102, PR China.
authors.forename: Zhi-hong
authors.initials: ZH
authors.lastname: Yao
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000367:Age Factors; D001299:Audiometry / Q000379:methods*; D001309:Auditory Threshold / Q000502:physiology*; D002681:China; D015331:Cohort Studies; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D006312:Hearing Loss, Bilateral / Q000175:diagnosis*; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D012017:Referral and Consultation / Q000706:statistics & numerical data; D018570:Risk Assessment; D012720:Severity of Illness Index; D014796:Visual Perception / Q000502:physiology*
keywords: Chirp-ABR threshold; Infants; VRA threshold