title: Sonar gain control in echolocating finless porpoises (Neophocaena phocaenoides) in an open water.
abstract: Source levels of echolocating free-ranging Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) were calculated using a range estimated by measuring the time delays of the signals via the surface and bottom reflection paths to the hydrophone, relative to the direct signal. Peak-to-peak source levels for finless porpoise were from 163.7 to 185.6 dB re: 1 microPa. The source levels are highly range, dependent and varied approximately as a function of the one-way transmission loss for signals traveling from the animals to the hydrophone.
authors.affiliation: Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China.
authors.forename: Songhai
authors.initials: S
authors.lastname: Li
authors.forename: Ding
authors.initials: D
authors.lastname: Wang
authors.forename: Kexiong
authors.initials: K
authors.lastname: Wang
authors.forename: Tomonari
authors.initials: T
authors.lastname: Akamatsu
mesh_terms: D000162:Acoustics; D000818:Animals; D003247:Conservation of Natural Resources; D004455:Echolocation / Q000502:physiology*; D004867:Equipment Design; D008432:Mathematical Computing; D019576:Porpoises / Q000502:physiology*; D014828:Vocalization, Animal; D014867:Water
chemical_list: D014867:Water