Patients suffering from conductive or mixed hearing loss may benefit from bone-anchored hearing aids (Baha). With only passively cooperative patients as young children objective methods (e.g. auditory evoked potentials - AEP) are requested to determine hearing loss and sucess of hearing aid fitting. The feasibility aspect of AEP determination with Baha-stimulation was examined. Ten normal-hearing subjects were provided with a Baha wich was temporarily connected with a Softband. Auditory brainstem responses (ABR) and cortically evoked responses (CAEP) were measured, tresholds determined and matched with the respective resonses evoked by earphone-stimulation. For ten patients suffering from sensorineural hearing loss objective hearing tresholds (0.5, 1, 2 kHz) were determined using CAEP-recording and matched with subjective hearing treshholds. The recording of ABR and CAEP using a Baha as stimulator is feasible. The specific waveforms are presentable and comparable to those evoked by earphone-stimulation. AEP-recording offers a possibility to estimate objective hearing tresholds (with limitations frequency specific) with Baha users.