Bearded seals (Erignathus barbatus) have a circumpolar Arctic distribution and are closely associated with unstable pack ice, spending nearly all of their lives in remote habitats. As a result, their biology and behavior remain largely unknown. With respect to sensory biology, bearded seals—like other marine mammals—rely on acoustic cues to support a range of vital behaviors. Acoustic monitoring from moored instrumentation has revealed a rich repertoire of underwater calls associated with the breeding season. However, the ability of bearded seals to perceive sound has never been investigated. In this study, species-typical auditory profiles were obtained from two young male bearded seals trained to cooperate in a go/no-go sound detection paradigm. Hearing thresholds were measured for underwater tonal sounds at frequencies between 0.1 and 61 kHz, in quiet conditions and in the presence of octave-band masking noise. The bearded seals displayed sensitive underwater hearing with peak sensitivity near 50 dB re 1 µPa and a broad frequency range of best hearing extending from approximately 0.3 to 45 kHz. Additionally, the two seals performed particularly well compared to other mammals when detecting target signals embedded within background noise; critical ratios ranged from 12 to 30 dB between 0.1 and 25.6 kHz. These findings improve understanding of the acoustic ecology of bearded seals, inform best management practices related to anthropogenic noise in Arctic habitats, and provide insight into comparative auditory capabilities within the lineage of phocid seals.

中文翻译：

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胡须海豹（Erignathus barbatus）的听觉生物学

胡须海豹（Erignathus barbatus）分布在北极圈，与不稳定的浮冰密切相关，几乎一生都生活在偏远的栖息地。因此，它们的生物学和行为在很大程度上仍然未知。在感官生物学方面，胡须海豹与其他海洋哺乳动物一样，依靠声学线索来支持一系列重要行为。系泊仪器的声学监测揭示了与繁殖季节相关的丰富水下叫声。然而，胡须海豹感知声音的能力从未被研究过。在这项研究中，从两只年轻的雄性胡须海豹获得了物种典型的听觉特征，这些海豹经过训练，可以在进行/不进行声音检测范式中进行合作。测量了频率在 0.1 到 61 kHz 之间的水下音调声音的听力阈值，在安静条件下和存在倍频程掩蔽噪声的情况下。胡须海豹表现出灵敏的水下听力，峰值灵敏度接近 50 dB re 1 µPa，最佳听力频率范围从大约 0.3 到 45 kHz。此外，与其他哺乳动物相比，这两种海豹在检测嵌入在背景噪音中的目标信号时表现尤其出色；0.1 至 25.6 kHz 之间的临界比率范围为 12 至 30 dB。这些发现提高了对胡须海豹声学生态学的理解，为与北极栖息地人为噪声相关的最佳管理实践提供信息，并提供了对海豹谱系内比较听觉能力的洞察。胡须海豹表现出灵敏的水下听力，峰值灵敏度接近 50 dB re 1 µPa，最佳听力频率范围从大约 0.3 到 45 kHz。此外，与其他哺乳动物相比，这两种海豹在检测嵌入在背景噪音中的目标信号时表现尤其出色；0.1 至 25.6 kHz 之间的临界比率范围为 12 至 30 dB。这些发现提高了对胡须海豹声学生态学的理解，为与北极栖息地人为噪声相关的最佳管理实践提供信息，并提供了对海豹谱系内比较听觉能力的洞察。胡须海豹表现出灵敏的水下听力，峰值灵敏度接近 50 dB re 1 µPa，最佳听力频率范围从大约 0.3 到 45 kHz。此外，与其他哺乳动物相比，这两种海豹在检测嵌入在背景噪音中的目标信号时表现尤其出色；0.1 至 25.6 kHz 之间的临界比率范围为 12 至 30 dB。这些发现提高了对胡须海豹声学生态学的理解，为与北极栖息地人为噪声相关的最佳管理实践提供信息，并提供了对海豹谱系内比较听觉能力的洞察。与其他哺乳动物相比，这两种海豹在检测嵌入背景噪声中的目标信号时表现特别出色；0.1 至 25.6 kHz 之间的临界比率范围为 12 至 30 dB。这些发现提高了对胡须海豹声学生态学的理解，为与北极栖息地人为噪声相关的最佳管理实践提供信息，并提供了对海豹谱系内比较听觉能力的洞察。与其他哺乳动物相比，这两种海豹在检测嵌入背景噪声中的目标信号时表现特别出色；0.1 至 25.6 kHz 之间的临界比率范围为 12 至 30 dB。这些发现提高了对胡须海豹声学生态学的理解，为与北极栖息地人为噪音相关的最佳管理实践提供信息，并提供了对海豹谱系内比较听觉能力的洞察。