obsolete absent brainstem auditory evoked potential true absent brainstem auditory brainstem response(s) MP:0004763 absent BAEP(s) absent brainstem evoked responses absent ABRs MPheno.ontology MP:0011967 absence of the synchronous electrical activity generated by neurons in the ascending auditory system that can be recorded from scalp electrograms by using computer-averaged responses to short tone bursts; by varying frequency, cochlear function can be assessed throughout the hearing range; normally, ABR thresholds vary with frequency, from a sound pressure level (SPL) of 35 dB at 5.6 kHz (a relatively low frequency for a mouse) to 15 dB at 45.2 kHz (a relatively high frequency); each 20 dB corresponds to a tenfold change in amplitude