Ambient noise causes independent changes in distinct spectro-temporal features of echolocation calls in horseshoe bats
Ambient noise causes independent changes in distinct spectro-temporal features of echolocation calls in horseshoe bats
复制标题
环境噪声导致马蹄蝠回声定位呼叫的独特频谱时间特征发生独立变化
DOI：
10.1242/jeb.102855
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发表时间：
2014-07-01
影响因子：
2.8
通讯作者：
Metzner, Walter
中科院分区：
文献类型：
--
作者：
Hage, Steffen R.;Jiang, Tinglei;Metzner, Walter
优化信噪比的最有效机制之一是伦巴第效应-由于环境噪声导致的呼叫幅度的不自觉上升。它往往伴随着变化的频谱时间组成的呼吁。我们研究了宽带滤波噪声对马蹄蝙蝠回声定位呼叫的频谱-时间组成的影响，该呼叫由恒定频率分量和初始和终端频率调制分量组成。我们发现，频率调制成分变得更大，几乎所有的噪声条件下，而恒定频率成分的带宽增加，只有当宽带滤波的噪声集中或以上的呼叫的主频率或基频。这表明，环境噪声独立修改相关的隆巴德效应的声学参数，如频谱时间特征，并可能显着影响蝙蝠的能力，以检测和定位目标。本研究结果对评价环境噪声对蝙蝠回声定位行为的影响具有重要意义。
One of the most efficient mechanisms to optimize signal-to-noise ratios is the Lombard effect - an involuntary rise in call amplitude due to ambient noise. It is often accompanied by changes in the spectro-temporal composition of calls. We examined the effects of broadband-filtered noise on the spectro-temporal composition of horseshoe bat echolocation calls, which consist of a constant-frequency component and initial and terminal frequency-modulated components. We found that the frequency-modulated components became larger for almost all noise conditions, whereas the bandwidth of the constant-frequency component increased only when broadband-filtered noise was centered on or above the calls' dominant or fundamental frequency. This indicates that ambient noise independently modifies the associated acoustic parameters of the Lombard effect, such as spectro-temporal features, and could significantly affect the bat's ability to detect and locate targets. Our findings may be of significance in evaluating the impact of environmental noise on echolocation behavior in bats.