Estimation of Direction of Arrival of Fish Calls in a Chorus Using Stereo Hydrophones

摘要

Some fish species produce sounds consisting of periodic pulses that are associated with distinct behaviors (e.g., courtship). Thus, the ability to estimate the direction of arrival from recorded sounds could provide insight into fish ecology and behavior. A stereo recording system was used to monitor underwater fish call sounds. The recorded signals were subjected to automatic processing to detect sounds that had the characteristics of fish calls. The direction of arrival for each detected sound was then estimated using the arrival time difference between the two hydrophones. Simulations confirmed that the recording system could accurately estimate the direction of arrival of fish call sounds. Furthermore, a blind source separation method was used to separate detected sounds originating from multiple individuals or groups of fish. Using this method, the direction of arrival for calls from multiple sources was estimated. The method described in this paper was successfully applied to monitor and isolate sounds from white croaker (Pennahia argentata) in the ocean.