Lin Chin-Feng, Chung Yao-Ching, Zhu Jin-De, Chang Shun-Hsyung, Wen Chan-Chuan, Parinov Ivan A, Shevtsov S N
Department of Electrical Engineering, National Taiwan Ocean University, Keelung City, Taiwan.
Department of Microeletronic Engineering, National Kaohsiung Marine University, Kaohsiung City, Taiwan.
J Acoust Soc Am. 2017 Aug;142(2):504. doi: 10.1121/1.4996106.
In this paper, a unique analysis method for sperm whale clicks based on Hilbert-Huang transform (HHT) is proposed. Four sperm whale click samples with durations of 10 ms (defined as click I), and four sperm whale click samples with durations of 5 ms (defined as click II) were illustrated. These click samples were recorded in the Mediterranean Sea by Centro Interdisciplinare di Bioacusticae Ricerche Ambientali, Università degli Studi di Pavia. The empirical mode decomposition method was used to decompose click I samples into seven intrinsic mode functions (IMFs) and one residue function (RF), and click II samples were decomposed into six IMFs and one RF. The average energy distributions of multiple IMFs and the single RF domain for click I and click II samples were explored using the HHT analysis method. The average energy-frequency representations were also investigated for the same click I and click II samples. The analysis results show that the energy-frequency characteristics of sperm whale clicks can be extracted and understood by applying several IMFs and one RF signal with a high-resolution analysis.
本文提出了一种基于希尔伯特-黄变换（HHT）的独特的抹香鲸咔嗒声分析方法。展示了四个持续时间为10毫秒的抹香鲸咔嗒声样本（定义为咔嗒声I），以及四个持续时间为5毫秒的抹香鲸咔嗒声样本（定义为咔嗒声II）。这些咔嗒声样本由帕维亚大学跨学科生物声学与环境研究中心在地中海记录。采用经验模态分解方法将咔嗒声I样本分解为七个本征模态函数（IMF）和一个残余函数（RF），咔嗒声II样本分解为六个IMF和一个RF。利用HHT分析方法探索了咔嗒声I和咔嗒声II样本的多个IMF和单个RF域的平均能量分布。还研究了相同的咔嗒声I和咔嗒声II样本的平均能量-频率表示。分析结果表明，通过应用几个IMF和一个具有高分辨率分析的RF信号，可以提取和理解抹香鲸咔嗒声的能量-频率特征。
