title: Directionality of sperm whale sonar clicks and its relation to piston radiation theory.
abstract: 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.
authors.forename: Kristian
authors.initials: K
authors.lastname: Beedholm
authors.forename: Bertel
authors.initials: B
authors.lastname: Møhl
mesh_terms: D000818:Animals; D004455:Echolocation / Q000502:physiology*; D008954:Models, Biological; D050661:Sperm Whale / Q000502:physiology*; D014465:Ultrasonics