Data from: Bats enhance their call identities to solve the cocktail party problem

Echolocating bats need to solve the problem of signal jamming by conspecifics when they are in a group. However, while several mechanisms have been suggested, it remains unclear how bats avoid confusion between their own echoes and interfering sounds in a complex acoustic environment. Here, we fixed on-board microphones onto individual frequency-modulating bats flying in groups. We found that group members broaden the inter-individual differences in the terminal frequencies of pulses, thereby decreasing the similarity of pulses among individuals. To understand what features most affect similarity between pulses, we calculated the similarity of signals mimicking pulses. We found that the similarity between those artificial signals was decreased most by manipulation of terminal frequency. These results demonstrate that the signal jamming problem is solved by this simple strategy, which may be universally used by animals that use active sensing, such as echolocating bats and electric fish, thereby transcending species and sensory modalities.

回声定位蝙蝠（echolocating bats）在群体活动时，需要解决同种个体造成的信号干扰问题。尽管已有多种潜在机制被提出，但目前仍不清楚蝙蝠如何在复杂声学环境中区分自身回声与干扰声源。本研究将机载麦克风（on-board microphones）固定于成群飞行的调频蝙蝠（frequency-modulating bats）个体身上。我们发现，群体成员会扩大声脉冲（pulses）终端频率的个体间差异，由此降低个体间声脉冲的相似性。为明确哪些特征对声脉冲间相似性影响最大，我们构建了模拟声脉冲的信号并计算其相似度。结果显示，通过调整终端频率可最大程度降低此类人工信号间的相似性。上述结果表明，蝙蝠通过这一简单策略解决了信号干扰问题，该策略可能被回声定位蝙蝠、电鱼（electric fish）等利用主动感知（active sensing）的动物广泛采用，从而跨越物种边界与感官模态（sensory modalities）的限制。