Sea Mammal Research Company (SEAMARCO), Julianalaan 46, 3843 CC Harderwijk, The Netherlands.
J Acoust Soc Am. 2018 Jun;143(6):3583. doi: 10.1121/1.5040493.
Seals exposed to intense sounds may suffer hearing loss. After exposure to playbacks of broadband pile-driving sounds, the temporary hearing threshold shift (TTS) of two harbor seals was quantified at 4 and 8 kHz (frequencies of the highest TTS) with a psychoacoustic technique. The pile-driving sounds had: a 127 ms pulse duration, 2760 strikes per h, a 1.3 s inter-pulse interval, a ∼9.5% duty cycle, and an average received single-strike unweighted sound exposure level (SEL) of 151 dB re 1 μPas. Exposure durations were 180 and 360 min [cumulative sound exposure level (SEL): 190 and 193 dB re 1 μPas]. Control sessions were conducted under low ambient noise. TTS only occurred after 360 min exposures (mean TTS: seal 02, 1-4 min after sound stopped: 3.9 dB at 4 kHz and 2.4 dB at 8 kHz; seal 01, 12-16 min after sound stopped: 2.8 dB at 4 kHz and 2.6 dB at 8 kHz). Hearing recovered within 60 min post-exposure. The TTSs were small, due to the small amount of sound energy to which the seals were exposed. Biological TTS onset SEL for the pile-driving sounds used in this study is around 192 dB re 1 μPas (for mean received SEL of 151 dB re 1 μPa and a duty cycle of ∼9.5%).
暴露于强烈声音下的海豹可能会遭受听力损失。在经受宽带打桩声音回放后，使用心理声学技术定量测量了两只斑海豹在 4 和 8 kHz（TTS 最高的频率）的暂时听阈偏移（TTS）。打桩声音具有：127 ms 的脉冲持续时间、2760 次/小时的冲击次数、1.3 s 的脉冲间隔、约 9.5%的占空比，以及 151 dB re 1 μPas 的平均单次未加权声暴露级（SEL）。暴露持续时间分别为 180 和 360 分钟[累积声暴露级（SEL）：190 和 193 dB re 1 μPas]。对照实验是在低环境噪声下进行的。只有在 360 分钟的暴露后才会出现 TTS（平均 TTS：海豹 02，声音停止后 1-4 分钟：4 kHz 时为 3.9 dB，8 kHz 时为 2.4 dB；海豹 01，声音停止后 12-16 分钟：4 kHz 时为 2.8 dB，8 kHz 时为 2.6 dB）。暴露后 60 分钟内听力恢复。由于海豹暴露的声能很少，TTS 很小。在这项研究中使用的打桩声音的生物 TTS 起始 SEL 约为 192 dB re 1 μPas（对于 151 dB re 1 μPa 的平均接收 SEL 和约 9.5%的占空比）。
