Whose Line Sound is it Anyway? Identifying the Vocalizer on Underwater Video by Localizing with a Hydrophone Array

Abstract

A new device that combined high-resolution (1080p) wide-angle video and three channels of high-frequency acoustic recordings (at 500 kHz per channel) in a portable underwater housing was designed and tested with wild bottlenose and spotted dolphins in the Bahamas. It consisted of three hydrophones, a GoPro camera, a small Fit PC, a set of custom preamplifiers and a high-frequency data acquisition board. Recordings were obtained to identify individual vocalizing animals through time-delay-of-arrival localizing in post-processing. The calculated source positions were then overlaid onto the video – providing the ability to identify the vocalizing animal on the recorded video. The new tool allowed for much clearer analysis of the acoustic behavior of cetaceans than was possible before.

Keywords

• Spotted dolphin
• Bottlenose dolphin
• Echolocation
• Vocalization
• Whistles
• Localization
• Stenella frontalis