Directionality of sperm whale sonar clicks and its relation to piston radiation theory

• Published in: The Journal of the Acoustical Society of America
• Main Authors: Beedholm, K., Møhl, Bertel
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2006
• Subjects: Sperm whale
• Online Access: https://pure.au.dk/portal/da/publications/directionality-of-sperm-whale-sonar-clicks-and-its-relation-to-piston-radiation-theory(de383fe0-dd1d-11db-bee9-02004c4f4f50).html; https://doi.org/10.1121/1.2161799

This paper investigates the applicability to sperm whales of the theory of sound radiating from a piston. The theory is applied to a physical model and to a series of sperm whale clicks. Results show that wave forms of off-axis signals can be reproduced by convolving an on-axis signal with the spatial impulse response of a piston. The angle of a recorded click can be estimated as the angle producing the spatial impulse response that gives the best match with the observation when convolved with the on-axis wave form. It is concluded that piston theory applies to sperm whale sonar click emission.