A influência do frênulo da língua na produção de fala

Abstract

The lingual frenulum (a small fold of mucous membrane that connects the sublingual face of the tongue to the floor of the mouth), when abnormal, can limit tongue movement and affect orofacial functions, such as speech. Distortions are frequently observed in the productions of alveolar tap [ɾ], alveolar lateral approximant [l], and consonant clusters containing [ɾ] and [l]. The aim of this study was to compare, from an acoustic perspective, the acoustic measurements (intensity and duration) of the consonant sounds [ɾ] and [l] and of surrounding vowels sounds in the speech production of individuals with and without lingual frenulum anomalies. The groups Research (presenting lingual frenulum anomalies) and Control (no lingual frenulum anomalies) were comprised of 9 children each, with ages between 7 and 12 years, selected from the same school in the city of São Paulo. Assessment of the lingual frenulum and recording sessions for speech samples (repetition of phrases containing the target sounds inserted in trisyllabic words) were conducted with both groups. The recordings were digitalized, and intensity (Δi) and duration for VCV units containing [a], [ɛ], [e] and [i] vowels (v), tap [ɾ] and lateral approximant [l] consonants (c) were automatically measured by a script written for the Praat software. Statistical analyses were based on the Generalized Additive Mixed Model (GAMM) and the Linear Generalized Mix Model-L (GLMM) for intensity and duration measurements, respectively. Complementary data of perceptive evaluation of vocal quality settings were added to the discussion of the findings. The intensity measurements (Δi) showed ample intra- and inter-speaker variation in the production of [l] and [ɾ] sounds, in Control and Research groups, especially in relation to the surrounding vowels (aperture degree), with little influence of the degree of frenulum abnormality. The duration measurements showed influence of frenulum abnormality, especially in moderate degrees. In their entirety, the findings signal individual mobilizations in the attempt to overcome mechanical limitations of tongue mobility imposed by lingual frenulum anomalies