Influence of the Spread of the Electric Field on Speech Recognition in Cochlear Implant Users

Abstract

Objective To investigate the correlation of word recognition with cochlear implant (CI) and spread of the electric field. Study Design Prospective, noninterventional, experimental study. Setting A tertiary referral center. Patients Thirty-eight adult CI users with poor (n = 11), fair (n = 13), and good (n = 16) word recognition performance. Main Outcome Measure Transimpedances were measured after 37 μs. Word recognition score was recorded at 65 dB SPL for German monosyllables in quiet. Transimpedance half widths were calculated as a marker for spread of the electric field. Results Narrow and broad spread of the electric field, i.e., small and large half widths, were observed in all word recognition performance groups. Most of the transimpedance matrices showed a pattern of expansion along the diagonal toward the apical electrode contacts. Word recognition was not correlated with transimpedance half widths. Conclusions The half width of the spread of the electric field showed no correlation with word recognition scores in our study population.