Comparison of mean threshold shifts induced by equivalent SL exposures ( SL) in air and under water for two duration conditions. There were no significant differences attributable to the differences in media.
A surface plot fitted to the mean threshold shifts under all conditions of noise level and duration. There is a significant interaction between noise SPL and duration for both phases of the experiment.
A plot of TTS in dB vs SEL in dB re , showing an exponential increase in magnitude of TTS with increasing exposure levels. The symbols represent mean shifts and the error bars represent standard deviations.
Recovery from TTS greater than plotted against the logarithm of time. All shifts eventually returned to near zero. Each line represents an individual test-recovery sequence. (b) A linear regression applied to the pooled data. The slope of the line is significant, , with a slope of per . The value is 0.54.
Noise exposure matrices for Phase 1 and Phase 2. The noise levels used are expressed in dB SL and dB SPL. The number of sessions conducted for the 16 level/duration combinations are provided, yielding a total of 112 exposure sequences for Phase 1 and 108 exposure sequences for Phase 2. The sound exposure levels resulting from each level/duration combination are shown in the cells.
The mean TTS values obtained for each cell of the noise exposure matrices used in Phases 1 and 2. Statistically significant threshold shifts are indicated as * , ** , and *** . Note that none of the control (no-noise) conditions generated significant TTS.
Temporary threshold shifts obtained at combinations of noise SL/duration. Equal sound exposure level conditions are grouped.
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