Fjord&Bælt and University of Southern Denmark, Margrethes Plads 1, 5300 Kerteminde, Denmark.
J Acoust Soc Am. 2011 Nov;130(5):3077-84. doi: 10.1121/1.3641434.
The biosonar pulses from free-ranging northern bottlenose whales (Hyperoodon ampullatus) were recorded with a linear hydrophone array. Signals fulfilling criteria for being recorded close to the acoustic axis of the animal (a total of 10 clicks) had a frequency upsweep from 20 to 55 kHz and durations of 207 to 377 μs (measured as the time interval containing 95% of the signal energy). The source level of these signals, denoted pulses, was 175-202 dB re 1 μPa rms at 1 m. The pulses had a directionality index of at least 18 dB. Interpulse intervals ranged from 73 to 949 ms (N = 856). Signals of higher repetition rates had interclick intervals of 5.8-13.1 ms (two sequences, made up of 59 and 410 clicks, respectively). These signals, denoted clicks, had a shorter duration (43-200 μs) and did not have the frequency upsweep characterizing the pulses of low repetition rates. The data show that the northern bottlenose whale emits signals similar to three other species of beaked whale. These signals are distinct from the three other types of biosonar signals of toothed whales. It remains unclear why the signals show this grouping, and what consequences it has on echolocation performance.
使用线列水听器阵记录了自由游动的北方瓶鼻海豚（Hyperoodon ampullatus）的生物声纳脉冲。满足记录在动物声轴附近的标准的信号（总共 10 个点击）具有从 20 到 55 kHz 的频率上升，持续时间为 207 到 377 μs（测量为包含信号能量 95%的时间间隔）。这些信号的声源级，记为脉冲，在 1 m 处为 175-202 dB re 1 μPa rms。这些脉冲的方向性指数至少为 18 dB。脉冲间隔范围为 73 至 949 ms（N=856）。重复率较高的信号具有 5.8-13.1 ms 的点击间隔（两个序列，分别由 59 和 410 个点击组成）。这些信号，记为点击，持续时间更短（43-200 μs），并且没有低重复率脉冲的频率上升特征。数据表明，北方瓶鼻海豚发出的信号类似于其他三种喙鲸的信号。这些信号与其他三种齿鲸的生物声纳信号明显不同。目前尚不清楚为什么信号会出现这种分组，以及这对回声定位性能有什么影响。
