Brainstem auditory evoked potential study was performed in 20 healthy young adults with earlobe recording and nasopharyngeal wall recording techniques. The peak latency, interpeak latency and amplitudes of five waves were evaluated to compare the clinical usability of the two methods and to understand the relationship between the waves and generator sources. Active electrode was placed at the ipsilateral earlobe with silver-silver chloride surface, disk electrode in earlobe recording technique. For nasopharyngeal wall recording, we designed specific recording electrodes which are made of silver bulb (diameter 2.5mm) with 10cm extended insulated lead. The tip of the recording electrode is placed at the nasopharyngeal wall through nasal cavity to approach anatomically closer site from the generator sources, brainstem. The reference electrode was placed at Fz in both methods. Nasopharyngeal wall recording reveals longer peak V latency, larger amplitude in peak II and IV, and smaller amplitude in peak III than ear-lobe recording (p<0.05). The difference may be originated from the change of anatomical and spatial orientation between active electrode and potential generator sources.
