Relationship Between Objective and Behavioral Audiology for Young Children Being Assessed for Cochlear Implantation: Implications for CI Candidacy Assessment.

OBJECTIVE

This study aimed to evaluate the feasibility of making cochlear implant recommendations based on diagnostic ABR and ASSR results. The goal was to challenge the need for behavioral audiometry as part of the standard cochlear implant assessment battery for infants with profound hearing loss and to reduce the age at which cochlear implant recommendation was made.

STUDY

DESIGN

A retrospective review of 123 patient files for children referred to the pediatric cochlear implant service before 3 years of age over a 3-year period was undertaken. Results for click-ABR, ASSR, and behavioral audiology at 500, 1k, 2k and 4k Hz, and tympanometry were collected and relationships were investigated for 64 children who met the inclusion criteria. Data were excluded for 59 children due to the presence of auditory neuropathy findings, middle ear pathology at the time of testing, if ASSR was not assessed at intensity levels >85 dB, and/or behavioral testing was judged to be unreliable by two experienced clinicians.

SETTING

Primary care pediatric cochlear implant program located within a hospital setting.

PATIENTS: Pediatric patients referred for cochlear implant evaluation before 3 years of age.

INTERVENTIONS(S): Children were assessed using ABR, ASSR, and behavioral audiometry for identification and confirmation of hearing loss.

MAIN OUTCOME MEASURES(S): Correlation between diagnostic click-ABR and ASSR thresholds and subsequently obtained behavioral hearing thresholds.

RESULTS

Results for objective measures (click-ABR and ASSR) were significantly correlated with behavioral results. The correlations, however, were poorer than expected with limited predictive value. For 6 of the 64 children click-ABR and/or ASSR suggested profound hearing loss and corresponding behavioral hearing threshold was found to be in the severe hearing loss range.

CONCLUSIONS

Findings of this study do not support making cochlear implant recommendations based on the findings of diagnostic click-ABR and ASSR alone. Investigating ways to reduce the average age children with severe-to-profound hearing loss receive a cochlear implant is a priority for the study institution. An alternate evaluation pathway for infants which incorporates a multifaceted assessment is warranted and will be the focus of future work at the study institution.