Localize Animal Sound Events Reliably (LASER): A New Software for Sound Localization in Zoos

Abstract

Locating a vocalizing animal can be useful in many fields of bioacoustics and behavioral research, and is often done in the wild, covering large areas. In zoos, however, the application of this method becomes particularly difficult, because, on the one hand, the animals are in a relatively small area and, on the other hand, reverberant environments and background noise complicate the analysis. Nevertheless, by localizing and analyzing animal sounds, valuable information on physiological state, sex, subspecies, reproductive state, social status, and animal welfare can be gathered. Therefore, we developed a sound localization software that is able to estimate the position of a vocalizing animal precisely, making it possible to assign the vocalization to the corresponding individual, even under difficult conditions. In this study, the accuracy and reliability of the software is tested under various conditions. Different vocalizations were played back through a loudspeaker and recorded with several microphones to verify the accuracy. In addition, tests were carried out under real conditions using the example of the giant otter enclosure at Dortmund Zoo, Germany. The results show that the software can estimate the correct position of a sound source with a high accuracy (median of the deviation 0.234 m). Consequently, this software could make an important contribution to basic research via position determination and the associated differentiation of individuals, and could be relevant in a long-term application for monitoring animal welfare in zoos.

Introducing the Software CASE (Cluster and Analyze Sound Events) by Comparing Different Clustering Methods and Audio Transformation Techniques Using Animal Vocalizations

“…To verify the quality of the clustering procedures, the vocalizations of both harpy eagles and giant otters were classified and labeled a priori. The giant otter vocalizations were linked to the corresponding individual emitting the vocalization via sound localization using the software LASER [ 56 ]. The exact experimental setup and method can be found in the publication on the software LASER [ 52 ].…”

From Soundwave to Soundscape: A Guide to Acoustic Research in Captive Animal Environments

“…To increase uptake in zoos, the novel hook is the conservation value of artificial intelligence; in other words, attracting the interest of conservation technologists who can study captive populations of threatened species. In fact, sound localization software in the field was recently modified for use in zoo enclosures; it works particularly well for loud and frequent vocalizing species with individual contact calls and a well-known vocal repertoire ( 149 ). Leading from this, there has been a small amount of wild research on soundmarks .…”

Discrimination of Acoustic Stimuli and Maintenance of Graded Alarm Call Structure in Captive Meerkats

“…Acoustic communication plays an important role in natural behavior, as sender and/or receiver can benefit from the meaning of the information contained in acoustic signals [ 7 ]. The information conveyed by acoustic signals from animals ranges from species identification, as in frogs and insects [ 8 ], to individual identification and personal traits, as in gibbons [ 9 , 10 ], banded mongoose [ 11 ], giant otters [ 12 , 13 ], or dolphins [ 14 ]; to contextual information such as resource availability, as in chimpanzee food calls [ 15 ]; or predator threat, as in meerkats [ 16 ], marmots [ 17 ], or primates [ 18 , 19 ]. Accordingly, a natural vocal repertoire in captive animals can provide extensive information about the physiological state, sex, subspecies, reproductive state, social status, stress, and animal welfare [ 20 ].…”