An inexpensive passive acoustic system for recording and localizing wild animal sounds

Abstract

An inexpensive animal recording and tracking system was designed, which uses sound-recording buoys deployed at several locations simultaneously in a passive hydrophone array. Each buoy contains a global positioning system ͑GPS͒ Location logger, a stereo digital audio tape ͑DAT͒ recorder with a hydrophone connected to one channel, and a VHF radio signal for time synchronization connected to the second channel. In a calibration test, three buoys were deployed in triangle formation at 1.8-km spacing. Light bulb implosions were localized to an accuracy of 60 m at the array center. These buoys are far less expensive than most marine acoustic tracking systems. The instrument package can be used for drift, moored, or terrestrial applications.

Spatial location influences vocal interactions in bullfrog choruses

“…This is unfortunate, because the biological task faced by females approaching an insect or anuran chorus is just that-discriminating individual acoustic elements within a large, complex auditory scene ͑Bee, 2007͒. Recently, several techniques based on the use of multiple microphone arrays have been introduced to enable large scale analysis and modeling of chorusing activity ͑McGregor et Hayes et al, 2000;D'Spain and Batchelor, 2006;Mennill et al, 2006;Mohan et al, 2008;Simmons et al, 2008;Jones and Ratnam, 2009͒. These techniques all attempt to automatically localize and discriminate many callers within a chorus based on both spatial location and the physical characteristics of their vocalizations.…”

Pair-wise processing of spectrograms for localization of multiple broadband CW sources

“…We consider arrays with a few hydrophones separated by many source wavelengths (sparse arrays) because they are usually the only type of array available to whale researchers. They are also, in general, the simplest and least costly tools for acoustic research [8]. Of further interest is that various sparse arrays currently in operation (e.g., AUTEC, PMRF, and the Southern California Offshore Acoustic Range) can be used to gather marine mammal data.…”

Sound Localisation in Practice: An Application in Localisation of Sick Animals in Commercial Piggeries

“…Previous research in relation to localisation of animal vocalisations has focused on localising animals in the wild (e.g. Hayes et al, 2000;Thomas et al, 2002) in order to mainly study animal behaviour. This chapter describes the steps that were followed in relation to sound localisation in commercial piggeries.…”