Echolocating bats exhibit differential amplitude compensation for noise interference at a sub-call level
Echolocating bats exhibit differential amplitude compensation for noise interference at a sub-call level
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DOI：
10.1242/jeb.225284
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发表时间：
2020-10-01
影响因子：
2.8
通讯作者：
Luo, Jinhong
中科院分区：
文献类型：
--
作者：
Lu, Manman;Zhang, Guimin;Luo, Jinhong
灵活的声音产生控制，使声音交流在有利和不利的条件。伦巴第效应（Lombard effect）是脊椎动物应对干扰噪声的一种广泛利用的策略，它描述了随着环境噪声的增加而增加的叫声幅度。在人类中，伦巴第效应通过在子音节水平上的差异振幅调制来影响词汇重音，迄今为止尚未在动物中有记录。在这里，我们用两种蝙蝠弥补了这一知识差距，这两种蝙蝠产生的回声定位呼叫由两个功能明确的单元组成：恒频（CF）和调频（FM）组件。我们发现，环境噪声在回声定位呼叫的CF和FM分量中诱导了强烈但不同的伦巴第效应。我们进一步报道，差幅补偿只发生在频谱重叠的噪声条件下，表明在释放掩蔽的功能作用。最后，我们发现两种蝙蝠在频谱无重叠噪声条件下都表现出强大的伦巴第效应，这与现有证据形成鲜明对比。我们的数据突出了蝙蝠的回声定位作为理解声音产生控制的潜在哺乳动物模型。
Flexible vocal production control enables sound communication in both favorable and unfavorable conditions. The Lombard effect, which describes a rise in call amplitude with increasing ambient noise, is a widely exploited strategy by vertebrates to cope with interfering noise. In humans, the Lombard effect influences the lexical stress through differential amplitude modulation at a sub-call syllable level, which so far has not been documented in animals. Here, we bridge this knowledge gap with two species of Hipposideros bats, which produce echolocation calls consisting of two functionally well-defined units: the constant-frequency (CF) and frequency-modulated (FM) components. We show that ambient noise induced a strong, but differential, Lombard effect in the CF and FM components of the echolocation calls. We further report that the differential amplitude compensation occurred only in the spectrally overlapping noise conditions, suggesting a functional role in releasing masking. Lastly, we show that both species of bats exhibited a robust Lombard effect in the spectrally non-overlapping noise conditions, which contrasts sharply with the existing evidence. Our data highlight echolocating bats as a potential mammalian model for understanding vocal production control.