BACKGROUND: The aim of the study was to investigate the potential and difference of pure tone audiogram, TEOAE and DPOAE in the detection of temporary threshold shift. METHODS: 46 disco visitors who were exposed to disco music at an average intensity of 105 dB (A) for 1, 1 1/2 and 2 hours respectively underwent audiological examination before and after noise exposure. Audiological measurements performed were an audiogram and measurements of the TEOAE and DPOAE using the system ILO 92 (Otodynamics). RESULTS: The frequency range where the threshold shift occurred was around 4000 Hz in the 1 hour group and spread over all frequencies when the exposure time increased. The average threshold shift over all frequencies and probands was 6.2 dB for the 1 hour group, 7.1 dB for the 1 1/2 hour group and 10.1 dB after 2 hours of noise exposure. TEOAE amplitudes showed significant reduction only at 2000 and 3000 Hz. Even at threshold shifts exceeding 15 dB, however not in all cases, a reduction of TEOAE amplitudes occurred. Similar results were obtained regarding the DPOAE measurements. CONCLUSIONS: We conclude that TEOAE and DPOAE are not ideal instruments in the detection of temporary threshold shift after noise exposure.
BACKGROUND: The aim of the study was to investigate the potential and difference of pure tone audiogram, TEOAE and DPOAE in the detection of temporary threshold shift. METHODS: 46 disco visitors who were exposed to disco music at an average intensity of 105 dB (A) for 1, 1 1/2 and 2 hours respectively underwent audiological examination before and after noise exposure. Audiological measurements performed were an audiogram and measurements of the TEOAE and DPOAE using the system ILO 92 (Otodynamics). RESULTS: The frequency range where the threshold shift occurred was around 4000 Hz in the 1 hour group and spread over all frequencies when the exposure time increased. The average threshold shift over all frequencies and probands was 6.2 dB for the 1 hour group, 7.1 dB for the 1 1/2 hour group and 10.1 dB after 2 hours of noise exposure. TEOAE amplitudes showed significant reduction only at 2000 and 3000 Hz. Even at threshold shifts exceeding 15 dB, however not in all cases, a reduction of TEOAE amplitudes occurred. Similar results were obtained regarding the DPOAE measurements. CONCLUSIONS: We conclude that TEOAE and DPOAE are not ideal instruments in the detection of temporary threshold shift after noise exposure.