Temporary Threshold Shifts Due to Short Tonal Over-Exposure

When the hearing is subjected to an non-damaging over-exposure, the absolute threshold of hearing shifts temporarily. The character (as a function of frequency and time) of a such shift gives information of the potential risk of a permanent damage for a similar sound with a longer duration and/or higher level. The observation of temporary threshold shift (TTS) may therefore be used in assessment of various' stimuli types potential for damaging the hearing. In this project, the TTS due to a short tonal over-exposure has been determined for a group of subjects, for frequencies at and around the frequency of the fatiguing sound. In another trial the TTS was monitored more accurately as a function of time for the frequency, for which the TTS was highest. A stochastic based model has been derived, which determines a TTS profile from non-simultaneous observations of the thresholds at different frequencies. Supported by STVF.