A Recording System for the Study of Tinnitus Through Auditory Evoked Potentials

Tinnitus is a consciously experienced ´ringing´ sensation in the auditory system, which occurs without the presence of an actual auditory stimulation. The study of tinnitus has resulted in a number of speculated mechanisms and suspected origins in the auditory pathway, however a definite model for this phenomenon has not been confirmed. In the majority of cases, external acoustic stimulation masks the tinnitus sensation and the offset of tinnitus is preceded by the complete withdrawal of acoustic stimulus. This paper describes a research effort to study the neurological expressions of tinnitus by analyzing auditory evoked potentials (AEP). The signals constituting the evoked response are many times smaller than the surrounding EEG signals. The paper describes the methodology and the instrument design to overcome this problem. The study concentrates in the analysis of AEP signals during silence, as well as the transitional nature of the AEP in order to identify possible EEG correlates of tinnitus