DOI: 10.5061/dryad.sf0nn
title: Data from: The noise egg: a cheap and simple device to produce low-frequency underwater noise for laboratory and field experiments

description: 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 of 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 are 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 broadband 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.
description: Recordings used for
 Figure 2Source level of five
 noise eggs measured at 1 m from the egg, at 1 m depth in a water column of
 approximately 2.5m above a muddy bottom.Recordings for
 Fig2.zipRecordings used for
 Figure 4Absolute sound pressure
 levels and relative particle velocity of five noise eggs measured at 50 cm
 from the egg. SPL in the field was recorded at 1 m depth in a water column
 of approximately 2.5 m above a muddy bottom. SPL and PVL of the egg were
 also recorded in a glass aquarium with a water depth of 40
 cm.Recordings for
 Fig4.zipRecordings used for
 Figure 5Propagation of sound
 pressure of the noise egg placed in a glass aquarium (See Fig. 3 for
 set-up). Absolute SPL was recorded at 10, 40 and 70 cm from the egg at two
 heights (H): 10 cm and 20 cm from the bottom. Recordings were made in
 water depths (D) of 30 cm and 40 cm. Recordings of ambient noise were made
 in the middle of the aquarium (40cm from the egg) and 20cm from the side
 (10 and 70cm from the egg) in the same water depths.Recordings for
 Fig5.zipRecordings used for
 Figure 6Propagation of particle
 velocity of the noise egg placed in a glass aquarium (See Fig. 3 for
 set-up). Relative PVL was recorded at 10, 40 and 70 cm from the egg at two
 heights (H): 10 cm and 20 cm from the bottom. Recordings were made in
 water depths (D) of 30 cm and 40 cm. Recordings of ambient noise were made
 in the middle of the aquarium (40cm from the egg) and 20cm from the side
 (10 and 70cm from the egg) in the same water depths.Recordings for
 Fig6.zipRecordings used for
 Supplementary Fig1Fig. S1. Recordings of
 particle velocity of a noise egg in a large aquarium measured for the egg
 used in the set-up (for description of the set-up, see material and
 methods). The noise egg was placed in the middle of the aquarium with its
 centre at a depth of 15 cm in 40 cm water. PVL was measured at three
 different depths: 10 cm (Z = -10), 20 cm (Z = 0) and 30 cm (Z = 10) and at
 four different distances (Y): 10, 20, 30 and 40 cm) to the right from the
 egg.Recordings for Suppl
 Fig1.zipRecordings used for
 Suppl Figure 2Recordings of different
 anthropogenic and natural sounds for comparison with the noise egg. Sounds
 were recorded in a shallow bay close to IMR Austevoll, Norway. All sounds
 were recorded with the same SM2+ recorder (www.wildlifeacoustics.com,
 Wildlife Acoustics, Inc., Maynard MA, USA; Sampling rate 48 kHz, to 16 bit
 WAV, 2 Hz high-pass filter, -115dBV equivalent input noise) and a standard
 hydrophone (HTI-96-MIN: Recording bandwidth: 2Hz – 48kHz, Sensitivity:
 -165dB re: 1 V/uPa).Recordings for Suppl
 Fig2.zip