A forma do som: um olhar aprofundado sobre a representação gráfica de ondas sonoras

• Ano de defesa: 2018
• Autor(a) principal: Rocha, Pedro Carvalho
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Bioacústica; Bioinformática; Anfíbios; Taxonomia dos Grupos Recentes
• Link de acesso: https://locus.ufv.br//handle/123456789/28410

Generally, bioacoustical studies still follow the same protocols implemented on the first half of the 20 th century. Moreover, most traditional call parameters are variable, subject to the influence of environmental factors and sexual selection. In light of this, methods of bioacoustic analyses need to improve the accuracy and precision in distinguishing between biological units with similar calls. We herein explore the previously described eigensound method and describe a new one: SoundShape. Both approaches rely on the acquisition of point coordinates (semilandmarks) from wave files, thus translating the spectrogram output into shape configurations that can be assessed by the broad range of tools from Geometric Morphometrics. Both methods were coded into R platform, with the description of two new functions SoundShape and eigensound. Moreover, the new eigensound function include some modifications from the original analysis so that it fits a broader range of animal sounds. SoundShape and eigensound functions were implemented on two empirical studies dealing with anuran advertisement calls from several Physalaemus species. Ordination plot (PCA) from both approaches yielded consistent structuring of biological groups (i.e. species and populations). SoundShape resulted in higher statistical power, whereas eigensound was more sensitive to the specificity of each species call. SoundShape is efficient for species ordination based on overall call similarity and is useful as a protocol for error verification in sound shape analysis. Eigensound is computationally more demanding, yet very sensitive to the sonic structure of calls, being able to describe the vocal signature of each individual. Thus, our study reiterates the biological meaning of the shape of sound and the applicability of Geometric Morphometrics approach in Bioacoustics.