Aerodynamic, eletroglottographic and acoustic measures of the voiced postalveolar fricative.

Abstract

Describe and correlate phonological and complementary measures regarding aerodynamics, electroglottography, acoustics, and perceptual judgment of production of the voiced fricative sound /ʒ/ comparing the performance of Brazilian Portuguese-speaking children with and without speech sound disorders. Study participants were 30 children aged 5 years to 7 years and 11 months divided into a group of children with typical development - Control Group (CG) and a group of children with speech sound disorders - Research Group (RG). Phonology (PCC, PCC-R, and occurrence of phonological processes) and the aerodynamic (amplitude of the oral airflow and f0), eletroglottographic (open quotient) and acoustic (classification of voicing) measures were evaluated. Numerically, children with speech sound disorders presented higher relative oral airflow amplitude, lower relative f0, and open quotient indicative of less efficient voicing production compared with those of children with typical development. The weak voicing values ​​showed that 66.1% of the children with speech sound disorders presented weaker voicing of the fricative sound /ʒ/ compared with that of the posterior vowel sound, and between-groups comparison demonstrated that these children presented greater difficulty in voicing. The acoustic analysis of speech used to classify the weak/strong voicing showed variations, especially regarding the classification partially devoiced. Results suggest that the strategies for voicing production and voicing maintenance of the fricative sound /ʒ/ are still variable in children aged 5 years to 7 years and 11 months; however, children with speech sound disorders seem to have more difficulties in using them effectively. In addition, the study shows the importance of applying complementary tests to obtain a more detailed diagnosis.