Electric auditory brain-stem responses in nucleus multichannel cochlear implant users.

OBJECTIVE

The electrically elicited auditory brain-stem response (EABR) has been proposed as a tool for use in cochlear implant device setting. To systematically examine the relationships of psychophysical perceptions and EABRs, implant users underwent a series of comparative measurements. The characteristics of the EABR were assessed for their predictive value in determining the subjective measures needed to set the implant device.

DESIGN

Characteristics of the EABR and various perceptual measures in a group of cochlear implant users served as compared variables in a correlational study.

SETTING

The study was carried out in the audiology clinic of a university hospital. The audiology clinic maintained a fully equipped evoked potential laboratory, and was part of an otolaryngology department that supported a cochlear implant program.

SUBJECTS

The subjects consisted of 10 consecutively selected postlinguistically deafened adult multichannel cochlear implant users.

MAIN OUTCOME MEASURES

Morphology, latency, and amplitude measures of the EABR recordings were compared with behavioral perceptions of threshold, most comfortable and uncomfortable loudness levels.

RESULTS

Perceptual measures of threshold were found to be significantly related to the threshold of the EABR across subjects and electrode position. Simple linear regression analysis was used to measure the degree of the relationship. An r value of 0.89 attests to a significant relationship. The EABR wave latencies and amplitudes were found to have no significant relationship to any of the perceptual measures examined.

CONCLUSIONS

Although EABR cannot replace behavioral measurements for device setting, in difficult cases EABR thresholds may be used as a starting point from which to estimate settings for the device.