Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
Department of Clinical Sciences and Center for Marine Sciences and Technology, College of Veterinary Medicine, North Carolina State University, Morehead City, North Carolina 28557, USA.
J Acoust Soc Am. 2024 May 1;155(5):3254-3266. doi: 10.1121/10.0026021.
Testudines are a highly threatened group facing an array of stressors, including alteration of their sensory environment. Underwater noise pollution has the potential to induce hearing loss and disrupt detection of biologically important acoustic cues and signals. To examine the conditions that induce temporary threshold shifts (TTS) in hearing in the freshwater Eastern painted turtle (Chrysemys picta picta), three individuals were exposed to band limited continuous white noise (50-1000 Hz) of varying durations and amplitudes (sound exposure levels ranged from 151 to 171 dB re 1 μPa2 s). Control and post-exposure auditory thresholds were measured and compared at 400 and 600 Hz using auditory evoked potential methods. TTS occurred in all individuals at both test frequencies, with shifts of 6.1-41.4 dB. While the numbers of TTS occurrences were equal between frequencies, greater shifts were observed at 600 Hz, a frequency of higher auditory sensitivity, compared to 400 Hz. The onset of TTS occurred at 154 dB re 1 μPa2 s for 600 Hz, compared to 158 dB re 1 μPa2 s at 400 Hz. The 400-Hz onset and patterns of TTS growth and recovery were similar to those observed in previously studied Trachemys scripta elegans, suggesting TTS may be comparable across Emydidae species.
龟鳖目动物受到多种胁迫因素的威胁，包括感官环境的改变。水下噪声污染有可能导致听力损失，并干扰对生物重要的声音线索和信号的检测。为了研究导致淡水东部锦龟（Chrysemys picta picta）产生暂时性阈移（TTS）的条件，将三只个体暴露于不同持续时间和强度的带限连续白噪声（50-1000 Hz）中（声暴露水平范围从 151 到 171 dB 重参考 1 μPa2 s）。使用听觉诱发电位法在 400 和 600 Hz 下测量和比较对照和暴露后的听觉阈值。在两种测试频率下，所有个体都发生了 TTS，听力损失为 6.1-41.4 dB。尽管两种频率的 TTS 发生次数相等，但在更高听觉敏感度的 600 Hz 下观察到的听力损失更大，而在 400 Hz 下观察到的听力损失更大。600 Hz 的 TTS 起始于 154 dB 重参考 1 μPa2 s，而 400 Hz 的 TTS 起始于 158 dB 重参考 1 μPa2 s。400-Hz 的 TTS 起始和 TTS 生长和恢复模式与之前研究的蛇颈龟（Trachemys scripta elegans）相似，这表明 TTS 在 Emydidae 物种之间可能具有可比性。
