Table 3.
Summary of studies showing short-term hearing changes and included in the meta-analysis.
| Authors (Publication Date) | Subjects (Ages) | Method | Main Outcomes | ||
|---|---|---|---|---|---|
| Study Design | ExposureIntensity | Exposure Time (min) | |||
| Bhagat and Davis (2008) [23] | 20 young adults (18–38 y) | Hearing statuses were measured pre, post (30 min), and recovery (48 h) from time of music exposure PTA OAEs (DPOAEs, SOAEs) |
85 dBC ± 3 dB | 30 | Although the hearing thresholds did not change, the changes in DPOAEs and SSOAEs were early warning signs of the harmful effects of high levels of music exposure on cochlear functioning. |
| Keppler and Bockstael (2010) [25] | Noise exposure group 15 young adults (19–28 y), Control group 28 young adults (19–28 y) |
Audiometric results of both groups were compared PTA OAEs (DPOAEs, TEOAEs) |
LAeq,1h 92.41 dBA LAeq,8h 83.38 dBA |
60 | In the noise exposure group, the PTA and TEOAE amplitudes changed significantly between pre- and post-exposure. However, these patterns were not found for the DPOAE amplitudes. |
| Le Prell et al. (2012) [20] | 33 young adults (18–27 y) | Hearing status was measured pre, post (15min, 75min, 135min, 195min), and recovery (following 1 day and 1 week) after music exposure PTA OAEs (DPOAEs) |
94.5 dBA (n = 10) 99.6 dBA (n = 11) 100.3 dBA (n =12) |
240 | Changes in hearing thresholds showed a notched configuration, largest at 4 kHz. After music exposure, small, but reliable, temporary threshold shifts were found, but these threshold shifts quickly recovered during the first 3 h after music exposure. |
| Keppler et al., (2014) [27] | 28 young adults (19–30 y) | Hearing status was measured pre- and post- (immediately, 30 min) exposure PTA OAEs (DPOAEs, TEOAEs) |
Based on LAeq,1h 82.52 dBA (n = 2) 87.46 dBA (n = 2) 92.25 dBA (n =12) 98.70 dBA (n = 12) |
60 | The authors reported that no clear relationship exists between temporary hearing deterioration and the amount of efferent suppression. |
| Torre and Grace (2014) [28] | Noise exposure group 101 young adults (18–30 y), Control group 21 young adults |
Audiometric results for both groups were compared for pre- and post- (immediate) exposure DPOAE absolute levels and generator and characteristic frequency component levels were noted |
50.8 dBA (n = 7) 56.6 dBA (n = 56) 58.8 dBA (n = 14) 62.3 dBA (n = 24) |
60 | Based on the lower listening levels, DPOAEs showed very little or indeed no significant change after music exposure. |
| Trzaskowski et al. (2014) [29] | 20 young adults (22–27 y) | Audiological tests were conducted pre-, post (immediately), and recovery (24 h) after music exposure PTA OAEs (DPOAEs, TEOAEs) |
86.6 dBA | 30 | No statistically significant changes were found in OAE and PTA following 30min of music exposure. |
| Narahari et al. (2017) [32] | 34 young adults (17–21 y) | DPOAEs at pre- and post- (2 h) music exposure were analyzed | 98.29 dBSPL | 120 | The DPOAEs were affected immediately post music exposure, especially at 8 kHz or higher. |
Note: y, years old; PTA, pure tone audiometry; OAEs, otoacoustic emissions; DPOAEs, distortion product otoacoustic emissions; SOAEs, spontaneous otoacoustic emissions; TEOAEs, transient-evoked otoacoustic emissions.