LOUDNESS BALANCE BETWEEN ACOUSTIC AND ELECTRIC-STIMULATION BY A PATIENT WITH A MULTICHANNEL COCHLEAR IMPLANT

Estimates of loudness balance were obtained for acoustically and elect rically presented 250 Hz sine signals from a patient who uses the Iner aid multichannel cochlear implant. Acoustic and electric loudness matc hing was possible because the patient evidenced a 25 dB HL threshold a t 250 Hz in his nonimplanted ear. The level of the electrical stimulus in microamperes required for a balance of loudness grew linearly with equal increments in decibels for the acoustic stimulus. These data, i n concert with the very limited data from previous studies, provide a rationale for using a logarithmic transformation of acoustic to electr ic intensity in signal processors for cochlear implants.