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. 2023 Aug 1;154(2):1003-1017. doi: 10.1121/10.0020588.
Noise pollution in aquatic environments can cause hearing loss in noise-exposed animals. We investigated whether exposure to continuous underwater white noise (50-1000 Hz) affects the auditory sensitivity of an aquatic turtle Trachemys scripta elegans (red-eared slider) across 16 noise conditions of differing durations and amplitudes. Sound exposure levels (SELs) ranged between 155 and 193 dB re 1 μPa2 s, and auditory sensitivity was measured at 400 Hz using auditory evoked potential methods. Comparing control and post-exposure thresholds revealed temporary threshold shifts (TTS) in all three individuals, with at least two of the three turtles experiencing TTS at all but the two lowest SELs tested, and shifts up to 40 dB. There were significant positive relationships between shift magnitude and exposure duration, amplitude, and SEL. The mean predicted TTS onset was 160 dB re 1 μPa2 s. There was individual variation in susceptibility to TTS, threshold shift magnitude, and recovery rate, which was non-monotonic and occurred on time scales ranging from < 1 h to > 2 days post-exposure. Recovery rates were generally greater after higher magnitude shifts. Sound levels inducing hearing loss were comparatively low, suggesting aquatic turtles may be more sensitive to underwater noise than previously considered.
水环境污染中的噪声会导致暴露于噪声中的动物听力损失。我们研究了持续的水下白噪声（50-1000Hz）是否会影响水生龟 Trachemys scripta elegans（红耳滑龟）在 16 种不同持续时间和幅度的噪声条件下的听觉灵敏度。声暴露水平（SEL）范围在 155 到 193dB 相对 1μPa2s，在 400Hz 使用听觉诱发电位方法测量听觉敏感性。比较对照和暴露后阈值，发现所有三个个体都有暂时阈值偏移（TTS），其中至少有两个个体在除了两个最低的 SEL 之外的所有测试 SEL 下都经历了 TTS，偏移高达 40dB。偏移幅度与暴露持续时间、幅度和 SEL 之间存在显著的正相关关系。平均预测 TTS 起始值为 160dB 相对 1μPa2s。个体对 TTS 的敏感性、阈值偏移幅度和恢复率存在差异，这种差异是非单调的，发生在暴露后从<1h 到>2 天的时间范围内。恢复率通常在较大幅度偏移后更高。导致听力损失的声级相对较低，这表明水生龟可能比以前认为的对水下噪声更敏感。
