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

• Main Author: Dresch, Andrea Alves Guimarães
• Publication Date: 2015
• Format: Master thesis
• Language: por
• Source: Repositório Institucional da UTFPR (da Universidade Tecnológica Federal do Paraná (RIUT))
• Download full: http://repositorio.utfpr.edu.br/jspui/handle/1/1799
• topic: 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

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.