OBJECTIVES: The aim of this prospective study was to investigate whether prior exposure to a low-level acoustic stimulus in patients with hearing loss requiring high-level acoustic stimulation could reduce the Temporary Threshold Shift (TTS), as observed in the aided ears of these patients when using hearing aids adjusted to high-level acoustic stimulation. MATERIALS AND METHODS: Thirteen (n=13) patients that showed increases in auditory threshold in the aided ears after using high-power hearing aids (HPHAs) were included in this study. Initially, the high-level acoustic stimulation (HLAS) was reduced to low-level acoustic stimulation (LLAS) demonstrated not to increase the hearing threshold. HPHAs were used for LLAS for 60-90 days. At that point, HPHA amplification settings were returned to baseline. TTS was measured several times throughout the study by comparing the patient´s hearing sensitivity response for pure tones by air conduction. Tests were performed twice on the same day, before and immediately after a 2.5-hr period of use, during which the hearing aid wasadjusted to generate HLAS. RESULTS: Statistical analysis (ANOVA) showed that the degree of TTS observed in aided ears fit with HPHAs was significantly reduced (f <0.0001) during the 60-90-day period when the amplification setting was set for LLAS. CONCLUSION: This study suggests that pre-exposure to non-damaging noise reduces the negative effects (TTS) observed in ears fit with high-power hearing aids.
