Evoked-potential audiograms were obtained in two (one male and one female) Yangtze finless porpoises, Neophocaena phocaenoides asiaseorientalis. Sinusoidal amplitude-modulated 20-ms tone bursts were used as probes with recording envelope-following evoked potentials. A frequency range of 8 to 152 kHz was investigated. The range of greatest sensitivity covered frequencies from 45 to 139 kHz, and the lowest thresholds of 47.2 and 48.5 dB re: 1 μ Pa were found at a frequency of 54 kHz in the two subjects, respectively. At lower frequencies, threshold increased with a rate of around 14 dB/octave, and threshold steeply increased at 152 kHz. © 2005 Acoustical Society of America.
1.Russian Acad Sci, Inst Ecol & Evolut, Moscow 119071, Russia 2.Chinese Acad Sci, Inst Hydrobiol, Wuhan 430072, Hubei, Peoples R China
Popov, VV; Supin, AY; Wang, D; Wang, KX; Xiao, JQ; Li, SH.Evoked-potential audiogram of the Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis (L),JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA,2005,117(5):2728-2731