National Marine Mammal Foundation, 2240 Shelter Island Drive, #204, San Diego, California 92106, USA.
Naval Facilities Engineering Systems Command Pacific, 528 Makalapa Drive Site 100, Honolulu, Hawaii 96860, USA.
J Acoust Soc Am. 2024 Oct 1;156(4):2527-2537. doi: 10.1121/10.0028626.
Continuous active sonar is thought to mitigate severe acoustic impacts due to its lower sound pressure level compared to pulsed active sonar typically used by world navies. However, due to its almost continuous duty cycle, continuous active sonar could have a higher potential for auditory masking. Here, we evaluate the auditory masking potential of several noise types including a recording of continuous active sonar, amplitude modulated noise, and Gaussian noise, on signal detection in two killer whales. Signals were either a 1.5 kHz pure tone or a recording of a broadband burst-pulse killer whale call. For the 1.5 kHz tone, all noise types resulted in statistically significant masking, however, there was a release from masking of approximately 13 dB for the amplitude-modulated noise. When the killer whale call was the signal, the whales employed an off-frequency listening strategy where the whales were able to detect frequency components of the signal that did not directly overlap with the noise. However, this strategy was less useful for the continuous active sonar noise due to its broadband harmonic structure. Continuous active sonar has spectral features that considerably overlap with those of killer whale calls, making this type of noise an effective auditory masker.
连续主动声纳被认为可以减轻严重的声冲击，因为与世界各国海军通常使用的脉冲主动声纳相比，其声压级较低。然而，由于其近乎连续的工作周期，连续主动声纳可能具有更高的听觉掩蔽潜力。在这里，我们评估了几种噪声类型的听觉掩蔽潜力，包括连续主动声纳的录音、调幅噪声和高斯噪声，以及在两只虎鲸中的信号检测。信号要么是 1.5 kHz 的纯音，要么是宽带脉冲虎鲸叫声的录音。对于 1.5 kHz 的音调，所有噪声类型都导致了统计学上显著的掩蔽，但调幅噪声的掩蔽释放了约 13 dB。当虎鲸叫声为信号时，鲸鱼采用了一种离频听觉策略，鲸鱼能够检测到信号的非直接与噪声重叠的频率分量。然而，由于连续主动声纳噪声的宽带谐波结构，这种策略对连续主动声纳噪声的效果较差。连续主动声纳具有与虎鲸叫声相当重叠的频谱特征，使其成为一种有效的听觉掩蔽器。
