11/18/2023 0 Comments Ultrasonic listening deviceThis array architecture consisted of two sub-arrays each having 8 microphones. Another concept of microphone arrays was introduced by Aubauer 19 and further developed by Holderied and von Helversen 20. Arrays of more microphones helped to understand beam dynamics while hunting 18. Adding another microphone in T-shaped arrays allowed 3D localization of bats 13, which facilitated the study of sonar sound beam directionality 16 and revealed that bats can actively adjust their field of view through their mouth gape 17. Other rather sparse arrays (3 microphones) were used to quantitatively describe echolocation calls and sound pressure levels for several bat species 14, 15. The evolution of microphone arrays started with simple arrays of only two microphones, which have been used to determine approach angles of bats in early studies on moth hearing 12, 13. Microphone arrays are perhaps most powerful when used to study echolocating animals. In large automated farms, microphone arrays help pinpoint the location of sick animals 11 based on typical sounds (e.g. Arrays deployed in laboratory settings have shown that female mice respond to courtship songs of conspecific males 8, helping to uncover genes involved in speech and language 9, 10. Large, spatially distributed arrays have revealed the dynamics of breeding bird phenology 5, 6 and complex mating behaviors such as duetting in songbirds 7. Microphone arrays have been used to answer important questions in biology. Combining the position of the animal with the amplitude of its call allows an estimate of the spatial emission pattern, or the sonar beam pattern in the case of an echolocating animal. Microphone arrays use the time difference of arrival ( TDoA) between synchronized microphones to triangulate the position of vocalizing animals 3, 4. Whether animals vocalize sparsely or constantly (as in echolocation), animal sounds provide an ideal means to track animal positions. Bats and cetaceans emit ultrasonic vocalizations and listen to the returning echoes for navigation and hunting 2. While in most species vocalizations are used for communication purposes, some species use sound for echolocation. Many animals use sound to transmit and receive signals and to acquire cues from their environment 1, 2. The flexible nature of the technology also makes it possible to create dense microphone arrays that can enhance our understanding in various fields of bioacoustics and can help to tackle the analytics of complex behaviors of vocalizing animals. Our technology makes it possible to do longer measurement campaigns over larger areas studying changing habitats and providing new insights for habitat conservation. We also demonstrate the flexibility of the proposed microphone array system in a second experiment, where we used a different array architecture allowing to simultaneously localize several species of vocalizing songbirds in a radius of 75 m. In a first experiment with hunting pallid bats the acoustic data acquired from a dense array with 64 microphones revealed details of the bats’ echolocation beam in previously unseen resolution. Here we show the development and application of large flexible microphone arrays that can be used to localize and track any vocalizing animal and study their bio-acoustic behavior. Important insights have been achieved through the use of microphone arrays, such as the convergent acoustic field of view in echolocating bats or context-dependent functions of avian duets. However, monitoring vocalizing animals through arrays of microphones, spatially distributed over their habitat has the advantage that unrestricted/unmanipulated animals can be observed. Studying free roaming animals usually requires setting up equipment over large areas and attaching a tracking device to the animal which may alter their behavior. Microphone arrays can be used for passive localization and tracking of sound sources while analyzing beamforming or spatial filtering of the emitted sound. Microphone arrays are an essential tool in the field of bioacoustics as they provide a non-intrusive way to study animal vocalizations and monitor their movement and behavior.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |