Data from: The noise egg: A cheap and simple device to produce low-frequency underwater noise for laboratory and field experiments

Studying the effect of anthropogenic noise on animal behaviour and physiology is a field of growing scientific and management interest. Anthropogenic noise is internationally seen as major environmental concern, but knowledge on the response of animals to noise and its ecological and evolutionary consequences is disparate. Even though fish and invertebrates form the majority of aquatic taxa, the effects of noise on these taxa are largely understudied. Especially the consequences of noise for short range communication and behavioural interactions is yet unknown. While experimental studies on this subject are thus greatly needed, the expense of the equipment can be a main factor limiting data generation. Speakers that produce low-frequency sounds under water are currently either too large or too expensive to allow for sufficient replication in many research set-ups. Here, we describe a device that can produce a low-frequency sound, which can be used as an experimental source of noise both in aquaria and in the field. The device is completely self-contained and costs around 10 euros per “noise egg”. The sound created consists of frequency bands (harmonics), which has the advantage that broad-band and pulsed sounds, such as sounds produced by vocal fish, are easily detected in a spectrogram. Because the sound from the egg attenuates quickly, it can be used in aquaria and in the field to target certain study species or individuals without affecting a large part of the surrounding area. We have developed the device to study the effects of noise on communication and behaviour in small aquatic animals, however, it could be used for other purposes, such as testing the propagation of certain frequencies in shallow water habitats. We hope the described method will facilitate the generation of experimental data on the effect of noise on behaviour and communication in aquatic animals in a wide variety of study systems and study areas.探究人为噪声(anthropogenic noise)对动物行为与生理机能的影响，是一个日益受到科研与管理领域关注的研究方向。人为噪声已被国际社会列为重大环境关切问题，但当前学界关于动物对噪声的响应及其生态与进化后果的认知仍较为零散。尽管鱼类与无脊椎动物构成了水生生物类群的绝大多数，但噪声对这些类群的影响仍研究不足，其中噪声对短距离通讯与行为交互的影响尤为未知。因此，该领域亟需开展相关实验研究，但实验设备的成本往往是制约数据产出的核心瓶颈。当前水下低频发声扬声器要么体积过大，要么成本高昂，难以在多数研究方案中实现充足的实验重复。 本文介绍一款可产生低频声音的完全自给式装置，可作为实验噪声源应用于水族箱与野外实验场景，单台“噪声蛋(noise egg)”的成本仅约10欧元。该装置发出的声音由多个频段（谐波harmonics）构成，这一特性使得宽带脉冲声（如发声鱼类产生的声音）可在声谱图(spectrogram)中被轻松识别。由于“噪声蛋”发出的声波衰减速度较快，因此可在水族箱或野外环境中精准针对特定研究物种或个体开展实验，不会对周边大范围区域产生干扰。本装置最初为探究噪声对小型水生动物通讯与行为的影响而开发，但也可拓展应用于其他研究场景，例如测试特定频率在浅水生境中的传播特性。我们期望本文介绍的方法能够助力科研人员在多样的研究体系与区域中，获取关于噪声对水生动物行为与通讯影响的实验数据。