Método para reconhecimento de vogais e extração de parâmetros acústicos para analises forenses

• Ano de defesa: 2015
• Autor(a) principal: Dresch, Andrea Alves Guimarães
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Tecnológica Federal do Paraná; Curitiba; Brasil; Programa de Pós-Graduação em Engenharia Biomédica; UTFPR
• Palavras-chave em Português: Fonética forense; Língua portuguesa - Vogais; Processamento de sinais - Modelos matemáticos; Teoria da previsão; Medição; Métodos de simulação; Engenharia biomédica; Forensic phonetics; Portuguese language - Vowels; Signal processing - Mathematical models; Prediction theory; Mensuration; Simulation methods; Biomedical engineering; CNPQ::ENGENHARIAS::ENGENHARIA BIOMEDICA::BIOENGENHARIA::PROCESSAMENTO DE SINAIS BIOLOGICOS
• Link de acesso: http://repositorio.utfpr.edu.br/jspui/handle/1/1799

Forensic speaker comparison exams have complex characteristics, demanding a long time for manual analysis. A method for automatic recognition of vowels, providing feature extraction for acoustic analysis is proposed, aiming to contribute as a support tool in these exams. The proposal is based in formant measurements by LPC (Linear Predictive Coding), selectively by fundamental frequency detection, zero crossing rate, bandwidth and continuity, with the clustering being done by the k-means method. Experiments using samples from three different databases have shown promising results, in which the regions corresponding to five of the Brasilian Portuguese vowels were successfully located, providing visualization of a speaker’s vocal tract behavior, as well as the detection of segments corresponding to target vowels.