Recording of electrically evoked auditory brainstem responses (E-ABR) with an integrated stimulus generator in Matlab

Electrical auditory brainstem responses (E-ABRs) of subjects with cochlear implants are used for monitoring the physiologic responses of early signal processing of the auditory system. Additionally, E-ABR measurements allow the diagnosis of retro-cochlear diseases. Therefore, E-ABR should be available in every cochlear implant center as a diagnostic tool. In this paper, we introduce a low-cost setup designed to perform an E-ABR as well as a conventional ABR for research purposes. The distributable form was developed with Matlab and the Matlab Compiler (The Mathworks Inc.). For the ABR, only a PC with a soundcard, conventional system headphones, and an EEG pre-amplifier are necessary; for E-ABR, in addition, an interface to the cochlea implant is required. For our purposes, we implemented an interface for the Combi 40+/Pulsar implant (MED-EL, Innsbruck).