A method and apparatus for utilizing the benefits of encoded signal transmission and reception to enhance the performance of medical testing devices (100) adapted to evoke and measure biological response signals such as auditory evoked potentials (AEP), and the auditory brainstem response (ABR) signals in particular. Auditory stimuli, such as clicks, are presented to the ear of a human patient, in a predetermined encoded sequence, resulting in the generation of auditory responses and bio-electric response signals in the human patient. These response signals from the patient are acquired and observed, and are processed according to the predetermined encoded sequence in which the auditory stimuli were presented to the patients ear in order to extract the desired auditory evoked potential signals or ABR signals.
