Purpose: to carry out an integrative literature review about the acoustic characteristics of healthy voice production, from childhood to old age. Methods: a bibliographic survey was conducted on the databases PubMed, SciELO, MEDLINE and LILACS, covering the last 10 years. Nineteen studies were found, meeting the proposed criteria, on acoustic measurements: F0 (fundamental frequency), jitter, shimmer and/or noise measurements, in males and females, with normal voices in their different stages of life. Results: the analysis showed that F0 is the most changing acoustic parameter as people grow up and grow old. Its values present gradual fall from childhood to old age in the female population, whereas among men such decrease lasts until adulthood. Jitter, shimmer and noise remain stable throughout childhood and adulthood, while shimmer and noise measurements increase in old age. In the literature, there is no consensus regarding increase of jitter measurements in the elderly. Conclusion: from childhood to old age, in both genders, vocal changes take place which are reflected, especially by F0. There is a scarcity of information on acoustics related to specific populations with ample age range, using the same methodology. The information in this study may guide future investigations aiming to understand natural changes occurring in the human voice, in addition to guiding in the clinical practice.

RESUMO Objetivo Caracterizar as vozes de indivíduos adultos sem queixas vocais e verificar o efeito de gênero e idade a partir de um conjunto de medidas acústicas. Método Foram analisadas 176 gravações de vozes pertencentes a adultos com idades entre 19 e 59 anos, divididas em quatro grupos etários, por década, armazenadas em uma base de dados. Todas as vozes analisadas foram classificadas com ausência de desvio na qualidade vocal. Realizou-se análise acústica dos parâmetros: Frequência Fundamental (vogal sustentada e fala encadeada), Jitter , Shimmer e Noise-to-Harmonic Ratio por meio software Multi Dimension Voice Program (KayPentax). O efeito de gênero, idade e possíveis interações foram verificados por meio do teste Anova Fatorial. Quando necessário, realizou-se post hoc com o teste Least Significant Difference. Resultados Houve mudanças na voz em função da idade, com diminuição da Frequência Fundamental nas modalidades vogal e fala encadeada em mulheres e na Frequência Fundamental da fala em homens. Em homens, foi observado aumento da medida de shimmer com o avanço da idade. Foram verificadas diferenças entre os gêneros nas medidas de Frequência Fundamental, Jitte r e Noise to Harmonic Ratio. Conclusão Mudanças vocais decorrentes do avanço da idade podem ser identificadas acusticamente, no final da fase adulta e, em mulheres, essas mudanças podem ser marcadas previamente ao período da menopausa.

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This study compares fundamental frequency (fo) and fundamental frequency standard deviation (foSD) of COVID-19 patients with the same parameters in the speech of subjects without COVID-19, and verifies whether there is an effect of age and sex in the patient group. Both groups, subjects with and without COVID-19, are formed by Brazilian Portuguese speakers. Speech samples were obtained from 100 patients with mild to severe symptoms of COVID-19, and 100 healthy subjects. A single 31-syllable Portuguese sentence was used as the elicitation material for all subjects. The recordings were divided into four age groups. The acoustic measures were semi-automatically extracted and analyzed by a series of analyses of variance. Patients with COVID-19 present vocal differences in fo-related parameters when compared to healthy subjects, that is, patient voices presented higher fo and foSD with respect to control voices. In addition, for patient voices, there was an age and sex effect on fo SD values. Vocal parameters of women and elderly subjects showed more marked differences in fo-related parameters, indicating that patient voices are higher-pitched and have a higher variation of fo SD. Consequently, fo-related parameters may be tested as vocal biomarkers in the screening of respiratory insufficiency by voice analysis, in patients with severe symptoms of COVID-19.

Purpose This study explored the role of auditory feedback in the regulation of oral–nasal balance in speakers of Brazilian Portuguese. Method Twenty typical speakers of Brazilian Portuguese (10 male, 10 female) wore a Nasometer headset and headphones while continuously repeating stimuli with oral and nasal sounds. Oral–nasal balance was quantified with nasalance scores. The signals from 2 additional oral and nasal microphones were played back to the participants through the headphones. The relative loudness of the nasal channel in the mix was gradually changed, so that the speakers heard themselves as more or less nasal. Results A repeated-measures analysis of variance of the mean nasalance scores of the stimuli at baseline, minimum, and maximum nasal feedback conditions demonstrated significant effects of nasal feedback condition ( p < .0001) and stimuli ( p < .0001). Post hoc analyses demonstrated that the mean nasalance scores were lowest for the maximum nasal feedback condition. The scores of the minimum nasal feedback condition were significantly higher than 2 of 3 baseline feedback conditions. The speaking amplitude of the participants did not change between the nasal feedback conditions. Conclusions Increased nasal signal level feedback led to a compensatory adjustment in the opposite direction, confirming that oral–nasal balance is regulated by auditory feedback. However, reduced nasal signal level feedback resulted in a compensatory response that was lower in magnitude. This suggests that, even in Brazilian Portuguese, a language with phonetic and phonological vowel nasalization, decreased nasality was not perceived as critically as increased nasality by the speakers.