Auditory brainstem response thresholds and functional hearing: implications for cochlear implant candidacy.

OBJECTIVE: This study assessed the relevance of auditory brainstem response (ABR) thresholds in evaluating cochlear implantation (CI) candidacy by studying their correlation with functional hearing in patients with sensorineural hearing loss (SNHL).

DESIGN AND STUDY SAMPLE: In this retrospective study, we examined correlations between ABR thresholds, speech perception scores in quiet and pure-tone audiometry in 191 adults. We compared these correlations between individuals with different degrees of SNHL to discern differences in potential CI candidates and individual with less severe SNHL.

RESULTS: A significant negative correlation was found between ABR thresholds and unaided speech perception scores at 70 dB SPL (R = -0.397, Pcorr<0.0001). For patients scoring 50% or higher on speech audiometry, a significant correlation was observed (R = -0.604, Pcorr<0.004), but not for those scoring less than 50% (R = -0.168, Pcorr=0.084). In the subgroup with ABR thresholds better than 60 dB nHL, a moderate correlation was observed (R = -0.575, Pcorr = 0.032), which was not significant in patients with ABR thresholds of 60 dB nHL or worse (R = -0.175, Pcorr = 0.084).

CONCLUSIONS: In patients with severe hearing loss (speech perception <50% or ABR thresholds ≥60 dB nHL), the ABR threshold does not correlate with speech perception, limiting its clinical validity for functional auditory performance or CI candidacy evaluation.