Effect of carrier bandwidth on integration of simulations of acoustic and electric hearing within or across ears

Abstract

Differences in current spread and/or spread of excitation may differently affect integration of acoustic and electric hearing within (electric-acoustic stimulation, or EAS) or across ears (bimodal). In this study, vowel recognition was measured in normal-hearing subjects listening to simulations of cochlear implant (CI), EAS, and bimodal listening. Residual acoustic hearing was limited between 0.1 and 0.6 kHz. The carrier bandwidth in the CI simulations was varied across carriers: broad-band noise, narrow-band noise, and sine waves. Results showed that reducing the bandwidth (and the inherent noise fluctuations) in the CI simulations significantly affected CI-only and bimodal performance, but not EAS performance.