Automated Classification of Dugong Calls and Tonal Noise by Combining Contour and MFCC Features
Automated Classification of Dugong Calls and Tonal Noise by Combining Contour and MFCC Features
复制标题
DOI：
10.1007/s40857-021-00234-5
复制
发表时间：
2021-04-10
影响因子：
1.7
通讯作者：
Mitamura，Hiromichi
中科院分区：
文献类型：
--
作者：
Tanaka，Kotaro;Ichikawa，Kotaro;Mitamura，Hiromichi
为了扩大动物被动声学监测的空间和时间尺度，在具有相似声学特性的噪声中自动检测目标声音是必要的，但也具有挑战性。特别是，音调发声和音调噪声的分类仍然是生物声学研究中的普遍问题。儒艮是一种栖息在沿海海域的濒临灭绝的海洋哺乳动物，需要对其发声进行监测，以增强我们对其栖息地利用的了解。然而，由于同一频带中存在音调噪声，检测儒艮的音调发声很困难。在这项研究中，为这些信号开发了一种分类方法，通过减少手动检查所需的劳动力来处理大量声学数据。提取梅尔频率倒谱系数（MFCC）来表征背景声音以及信号轮廓的一些参数，并训练支持向量机进行二元分类。即使在嘈杂的浅海环境中，分类器在测试数据集上也能实现 84.4% 的召回率和 93.5% 的精度。该方法通过结合轮廓和MFCC特征，能够对儒艮叫声和类似音调噪声进行有效分类，并且可以扩展濒危儒艮声学监测的空间和时间尺度。该技术可能适用于监测其他发出音调发声的濒临灭绝的海洋哺乳动物。
To expand the spatial and temporal scales of passive acoustic monitoring of animals, automatically detecting target sounds among noises with similar acoustic properties is essential but challenging. In particular, the classification of tonal vocalisations and tonal noise remains a universal problem in bioacoustics research. The vocalisations of dugong, which is an endangered marine mammal that inhabits coastal seas, need to be monitored to enhance our understanding of its habitat use. However, detecting dugong tonal vocalisations is difficult due to the presence of tonal noise in the same frequency band. In this study, a classification method was developed for these signals to handle large acoustic data by reducing the labour required for manual inspection. Mel-frequency cepstral coefficients (MFCC) were extracted to characterise background sounds along with a few parameters of the signal contour, and a support vector machine was trained for binary classification. The classifier achieved an 84.4% recall and a 93.5% precision on the testing dataset even in a noisy shallow marine environment. This methodology enables the effective classification of dugong calls and similar tonal noises by combining contour and MFCC features and can extend the spatial and temporal scale of acoustic monitoring of the endangered dugong. This technique is potentially applicable to the monitoring of other endangered marine mammals that produce tonal vocalisations.