Tese
Características vocais espectrográficas de crianças sem disfonia
Fecha
2019-02-28Autor
Hoffmann, Carla Franco
Institución
Resumen
Objective: to describe the maximum phonation times and the spectral acoustic vocal
characteristics of children without dysphonia from 4:00 to 7:11 years of age and to correlate them
with age, height and sex. Methods: transversal, quantitative, retrospective study in database.
Data were collected on the height, sex and age of 299 children. The records of the maximum
phonation times of the vowels / a /, / i /, / u / and of the vocal spectroscopy were analyzed.
Results: positive correlation between harmonic replacement by noise at low frequencies and time
of / a /; negative correlation between the intensity of the tracing of the fourth formant and the
entire spectrogram and bandwidth of the first formant with the time of / u /; positive correlation
between anti-resonance soon after the first formants and at high frequencies with time of / u /. In
narrow band spectra, intensity, harmonic substitution by noise, definition and regularity of
harmonics had a higher mean at low frequencies; the presence of noise was higher in the
medium frequencies; number of harmonics and presence of higher sub-harmonics at high
frequencies. In broad band spectra, the intensity was higher in the second formant; definition and
width were greater in the first formant; regularity at low frequencies and anti-resonance were
higher at high frequencies. No differences were found in narrowband and broadband spectra
according to sex; most of the bandwidth measurements presented negative correlation with age
and height, positive correlation between harmonic substitution by noise at low frequencies and
time of / a /, negative correlation between intensity of the fourth formant throughout the
spectrogram and width of the first formant with time of / u /, positive correlation between antiresonance soon after the first formants and at high frequencies with time of / u /. Conclusion: the
maximum phonation times of the children were within the values of the literature and were
influenced by height and age. Most of the spectrographic aspects evaluated were classified in a
mild degree. Characteristics such as hoarseness, nasality and breathiness in a mild degree are
considered normal for children, as occurred in this study. The increase in vowel time / a / showed
a higher presence of noise and the increase of / u / showed increase of anti-resonance and lower
color intensity of the tracing, evidencing loss of vocal quality with the time of support. Broadband
and broad band spectra were not influenced by sex, but broad band measurements were
influenced by height and age.