Comparison of fundamental frequency and formants frequency measurements in two speech tasks

ABSTRACT Purpose: to compare the measurements of fundamental frequency (F0) and frequency of the first two formants (F1 and F2) of the seven oral vowels of the Brazilian Portuguese in two speech tasks, in adults without voice and speech disorders. Methods: eighty participants in the age range 18 and 40 years, paired by gender, were selected after orofacial, orthodontic and auditory-perceptual assessments of voice and speech. The speech signals were obtained from carrier phrases and sustained vowels and the values of the F0 and frequencies of F1 and F2 were estimated. The differences were verified through the t Test, and the effect size was calculated. Results: differences were found in the F0 measurements between the two speech tasks, in two vowels in males, and in five vowels, in females. In the F1 frequencies, differences were noted in six vowels, in men, and in two, in women. In the F2 frequencies, there was a difference in four vowels, in men, and three, in women. Conclusion: based on the differences found, it is concluded that the speech task for evaluation of fundamental frequency and formants’ frequencies, in the Brazilian Portuguese, can show distinct results in both glottal and supraglottal measures in the production of different oral vowels of this language. Thus, it is suggested that clinicians and researchers consider both forms of emission for a more accurate interpretation of the implications of these data in the evaluation of oral communication and therapeutic conducts.