Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093-0701, USA.
J Acoust Soc Am. 2012 Apr;131(4):2682-99. doi: 10.1121/1.3685790.
Conventional detection of humpback vocalizations is often based on frequency summation of band-limited spectrograms under the assumption that energy (square of the Fourier amplitude) is the appropriate metric. Power-law detectors allow for a higher power of the Fourier amplitude, appropriate when the signal occupies a limited but unknown subset of these frequencies. Shipping noise is non-stationary and colored and problematic for many marine mammal detection algorithms. Modifications to the standard power-law form are introduced to minimize the effects of this noise. These same modifications also allow for a fixed detection threshold, applicable to broadly varying ocean acoustic environments. The detection algorithm is general enough to detect all types of humpback vocalizations. Tests presented in this paper show this algorithm matches human detection performance with an acceptably small probability of false alarms (P(FA) < 6%) for even the noisiest environments. The detector outperforms energy detection techniques, providing a probability of detection P(D) = 95% for P(FA) < 5% for three acoustic deployments, compared to P(FA) > 40% for two energy-based techniques. The generalized power-law detector also can be used for basic parameter estimation and can be adapted for other types of transient sounds.
传统的座头鲸叫声检测通常基于带限声谱图的频率求和，假设能量（傅里叶幅度的平方）是合适的度量标准。幂律检测器允许更高的傅里叶幅度幂次，当信号占据这些频率的有限但未知子集时，这种方法是合适的。船舶噪声是非平稳的、有色的，对许多海洋哺乳动物检测算法来说是个问题。引入了对标准幂律形式的修改，以最大程度地减少这种噪声的影响。这些相同的修改还允许使用固定的检测阈值，适用于广泛变化的海洋声环境。检测算法足够通用，可以检测所有类型的座头鲸叫声。本文提出的测试表明，即使在最嘈杂的环境中，该算法的假警概率（P(FA) < 6%）与人类检测性能相匹配，可接受性较小。与基于能量的两种技术相比，该检测器在三个声学部署中实现了 P(D) = 95%，P(FA) < 5%，而能量检测技术的 P(FA) > 40%。广义幂律检测器还可用于基本参数估计，并可适应其他类型的瞬态声音。
