R088: Effects of Stimulus Duration on the Wave V and N1 Peak

Abstract

metric thresholds, presence of TOAE and no history of head trauma, neurological disease or ear surgery took part in three random experiments in a soundproof booth. Subjects were instructed: (1) to solve Hanoi Tower problem (cognitive task, silence, no selective auditory attention); (2) to see if they might (or not) detect some sounds (selective auditory attention); (3) to see if they might (or not) detect some change on lightness (visual attention to evaluate the degree of suggestion). All experiments were performed for 5 minutes each. No sound or light changes were presented at all, but after each experiment, participants were asked about their perceptions of sound and light change. RESULTS: Some auditory perception was present in 19,7% of the subjects during Hanoi Tower experiment, in 45,5% under visual attention and in 69,7% under auditory attention (pϽ0.001). Silence without auditory attention was more related to common tinnitus-like perceptions (hissing, buzzing, humming, etc), while silence and auditory attention elicited more uncommon tinnitus-like perceptions, including some similar to auditory hallucinations (music, steps, people talking). CONCLUSION: Silence and auditory attention are important to elicit phantom auditory perceptions, especially when both situations are combined. Descriptions of auditory perceptions were different among experiments and may allow some differentiation between tinnitus and auditory hallucinations. SIGNIFICANCE: This study revisited the concept that tinnitus may be a subclinical symptom, but stated a more realistic rate of occurrence in normal hearing subjects. SUPPORT: Grant from CNPq (Brazil) R087 Auditory Notches in 134 Band Audiograms Sangyeop Kwak, MA (presenter); Eunyee Kwak, PhD