Medidas cepstrais na avaliação da intensidade do desvio vocal / Cepstral measures in the assessment of severity of voice disorders

RESUMO Objetivo Analisar se existe associação entre a presença, a intensidade e o tipo de desvio vocal e as medidas cepstrais em amostras de indivíduos com queixa vocal. Método Foram utilizadas 376 amostras da vogal /ε/ de indivíduos de ambos os gêneros, com queixa vocal. Utilizou-se uma escala analógico-visual para análise perceptivo-auditiva das vozes quanto à intensidade do desvio vocal (GG), graus de rugosidade (GR), soprosidade (GS) e tensão (GT), incluindo-se a determinação da qualidade vocal predominante (rugosa, soprosa ou tensa). Foram extraídas as medidas relacionadas ao Cepstral Peak Prominence-Smoothed (CPPS) e o declínio espectral das amostras vocais. Resultados Houve diferença dos valores do CPPS entre os grupos com e sem desvio vocal, assim como entre as diferentes intensidades e tipos de desvio vocal. Os valores do CPPS foram mais reduzidos em função da presença e intensidade do desvio vocal. Os valores do CPPS diferenciaram vozes rugosas x soprosas, rugosas x tensas e soprosas x tensas. O declínio espectral apenas diferenciou vozes soprosas x tensas. O CPPS se correlacionou de modo positivo e forte com os GG e GS, de modo negativo moderado com o GR, e de forma negativa fraca com o GT. O declínio espectral apresentou correlação positiva moderada com o GT e correlação negativa fraca com o GS. Conclusão Existe associação entre a presença de desvio vocal, o GG, a qualidade vocal predominante e o CPPS. De modo especial, o GG é fortemente correlacionado ao CPPS. O declínio espectral está associado apenas aos parâmetros de soprosidade e tensão.

ABSTRACT Purpose To analyze whether there is an association between the presence, intensity and type of voice disorder and the cepstral measures in samples of individuals with voice complaints. Methods We used 376 vowel /Ɛ/ samples from individuals of both genders that had voice complaints. An analogue-visual scale was used for the auditory-perceptual analysis of voices regarding the overall grade of dysphonia (G) and the grades of roughness (R), breathiness (B), and strain (S), including a determination of voice quality (rough, breathy or strained). Measures related to cepstral peak prominence smoothed (CPPS) and spectral decline of vocal samples were extracted. Results There were differences in the CPPS values between the groups with or without voice disorders as well as between the different intensities and types of voice disorder. CPPS values were lower because of the presence and intensity of voice disorders. The CPPS values differentiated the following voices: rough x breathy, rough x strained, and breathy x strained. The spectral decline only differentiated breathy x strained voices. CPPS correlated positively and strongly with G and B; moderately and negatively with R, and negatively and weakly with S. The spectral decline had a moderate positive correlation with S and a weak negative correlation with B. Conclusion There is association between voice disorder, G, predominant voice quality, and CPPS. In particular, G is strongly correlated with CPPS. Spectral decline is associated only with the parameters B and S.

KSG estimation of reconstruction delay to detect vocal disorders in nonlinear dynamical analysis

Abstract Introduction This research investigates the applicability of a relatively new estimator of mutual information, KSG estimator, to find the reconstruction delay of phase space in dynamical systems. There are evidences that the KSG estimator is more accurate than the naive method commonly used. Methods In this paper we estimated mutual information between the voice signals and their delayed versions, with KSG method. The voice signals were obtained from a disordered voice database. Then, we found the reconstruction delay where mutual information reached its first minimum. We applied the encountered value of reconstruction delay in linear discriminant analysis, in order to discriminate between healthy and pathological voices or to discriminate between pathologies. Discrimination between voice pathologies using nonlinear measurements is still not much explored. Moreover, in this paper we used a single nonlinear measurement: reconstruction delay. Results The results show that the reconstruction delay obtained with KSG method has increased classification rates in most cases, in terms of accuracy, sensitivity and specificity, when compared to the naive estimator usually adopted. Conclusion The KSG estimator is a promising technique to improve the diagnosis of voice related pathologies.

Acurácia das medidas acústicas tradicionais e formânticas na avaliação da qualidade vocal / Accuracy of traditional and formant acoustic measurements in the evaluation of vocal quality

RESUMO Objetivo Investigar a acurácia das medidas acústicas, isoladas e combinadas, na discriminação da intensidade do desvio vocal (GG) e da qualidade vocal predominante (QVP) em pacientes disfônicos. Método Participaram 302 pacientes do gênero feminino, com queixa vocal. A partir da vogal /ɛ/ sustentada, foram extraídas as medidas acústicas de média e desvio padrão (DP) da frequência fundamental (F0), o jitter, o shimmer e o Glottal to noise excitation (GNE) e a média dos três primeiros formantes (F1, F2, F3). A avaliação perceptivo-auditiva do GG e QVP foi realizada por três fonoaudiólogos especialistas em voz. Resultados Isoladamente, apenas o GNE obteve desempenho satisfatório na discriminação do GG e da QVP. Houve uma melhora na classificação do GG e QVP com a combinação das medidas acústicas. A média de F0, F2 e GNE (saudável × desvio leve a moderado), DP de F0, F1 e F3 (leve a moderado × desvio moderado), Jitter e GNE (moderado × desvio intenso) foram as melhores combinações para discriminar o GG. As melhores combinações para discriminação da QVP foram média de F0, Shimmer e GNE (saudável × rugosa), F3 e GNE (saudável × soprosa), média de F0, F3 e GNE (rugosa × tensa), média de F0, F1 e GNE (soprosa × tensa). Conclusão De forma isolada, o GNE mostrou-se o único parâmetro acústico capaz de discriminar o GG e a QVP. Houve um ganho no desempenho da classificação com a combinação das medidas acústicas tradicionais e formânticas, tanto para a discriminação do GG como da QVP.

ABSTRACT Purpose Investigate the accuracy of isolated and combined acoustic measurements in the discrimination of voice deviation intensity (GD) and predominant voice quality (PVQ) in patients with dysphonia. Methods A total of 302 female patients with voice complaints participated in the study. The sustained /ɛ/ vowel was used to extract the following acoustic measures: mean and standard deviation (SD) of fundamental frequency (F0), jitter, shimmer, glottal to noise excitation (GNE) ratio and the mean of the first three formants (F1, F2, and F3). Auditory-perceptual evaluation of GD and PVQ was conducted by three speech-language pathologists who were voice specialists. Results In isolation, only GNE provided satisfactory performance when discriminating between GD and PVQ. Improvement in the classification of GD and PVQ was observed when the acoustic measures were combined. Mean F0, F2, and GNE (healthy × mild-to-moderate deviation), the SDs of F0, F1, and F3 (mild-to-moderate × moderate deviation), and mean jitter and GNE (moderate × intense deviation) were the best combinations for discriminating GD. The best combinations for discriminating PVQ were mean F0, shimmer, and GNE (healthy × rough), F3 and GNE (healthy × breathy), mean F 0, F3, and GNE (rough × tense), and mean F0 , F1, and GNE (breathy × tense). Conclusion In isolation, GNE proved to be the only acoustic parameter capable of discriminating between GG and PVQ. There was a gain in classification performance for discrimination of both GD and PVQ when traditional and formant acoustic measurements were combined.