Fitting prelingually deafened adult cochlear implant users based on electrode discrimination performance

• Published in: International journal of audiology Vol. 56; no. 3; pp. 174 - 185
• Main Authors: Debruyne, Joke A., Francart, Tom, Janssen, A. Miranda L., Douma, Kim, Brokx, Jan P.L.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 04-03-2017
• Subjects: Acoustic Stimulation; Adult; Audiometry, Pure-Tone; Audiometry, Speech; Cochlear implant; Cochlear implant fitting; Cochlear Implantation - instrumentation; Cochlear Implants; Comprehension; Deafness - diagnosis; Deafness - physiopathology; Deafness - psychology; Deafness - rehabilitation; Discrimination (Psychology); Electrode discrimination; Female; Hearing; Humans; Loudness Perception; Male; Middle Aged; Persons With Hearing Impairments - psychology; Persons With Hearing Impairments - rehabilitation; Prelingual deafness; Prosthesis Design; Prosthesis Fitting; Psychoacoustics; Sound Spectrography; Spectral ripple discrimination; Speech Intelligibility; Speech Perception; Surveys and Questionnaires; Treatment Outcome; Psychoacoustics; Electrode discrimination; Cochlear implant; Prelingual deafness; Cochlear implant fitting; Spectral ripple discrimination; Speech perception
• ISSN: 1499-2027; 1708-8186
• DOI: 10.1080/14992027.2016.1243262

Objective: This study investigated the hypotheses that (1) prelingually deafened CI users do not have perfect electrode discrimination ability and (2) the deactivation of non-discriminable electrodes can improve auditory performance. Design: Electrode discrimination difference limens were determined for all electrodes of the array. The subjects' basic map was subsequently compared to an experimental map, which contained only discriminable electrodes, with respect to speech understanding in quiet and in noise, listening effort, spectral ripple discrimination and subjective appreciation. Study Sample: Subjects were six prelingually deafened, late implanted adults using the Nucleus cochlear implant. Results: Electrode discrimination difference limens across all subjects and electrodes ranged from 0.5 to 7.125, with significantly larger limens for basal electrodes. No significant differences were found between the basic map and the experimental map on auditory tests. Subjective appreciation was found to be significantly poorer for the experimental map. Conclusions: Prelingually deafened CI users were unable to discriminate between all adjacent electrodes. There was no difference in auditory performance between the basic and experimental map. Potential factors contributing to the absence of improvement with the experimental map include the reduced number of maxima, incomplete adaptation to the new frequency allocation, and the mainly basal location of deactivated electrodes.