Auditory steady-state response in cochlear implant patients

Abstract Introduction and objective Auditory steady state responses to continuous amplitude modulated tones at rates between 70 and 110 Hz, have been proposed as a feasible alternative to objective frequency specific audiometry in cochlear implant subjects. The aim of the present study is to obtain physiological thresholds by means of auditory steady-state response in cochlear implant patients (Clarion HiRes 90K), with acoustic stimulation, on free field conditions and to verify its biological origin. Methods 11 subjects comprised the sample. Four amplitude modulated tones of 500, 1000, 2000 and 4000 Hz were used as stimuli, using the multiple frequency technique. The recording of auditory steady-state response was also recorded at 0 dB HL of intensity, non-specific stimulus and using a masking technique. Results The study enabled the electrophysiological thresholds to be obtained for each subject of the explored sample. There were no auditory steady-state responses at either 0 dB or non-specific stimulus recordings. It was possible to obtain the masking thresholds. A difference was identified between behavioral and electrophysiological thresholds of −6 ± 16, −2 ± 13, 0 ± 22 and −8 ± 18 dB at frequencies of 500, 1000, 2000 and 4000 Hz respectively. Conclusions The auditory steady state response seems to be a suitable technique to evaluate the hearing threshold in cochlear implant subjects.