Analysis of Dental Sound Production /t/ and /d/ by Deaf Speakers

Abstract

This study examines in depth how deaf children pronounce the dental sounds /t/ and /d/ followed by the vowels /a/ and /i/. The focus is on consonant-vowel articulation patterns, variations in vowel transitions, and deviations resulting from hearing limitations. Six deaf children participated, with segmental phonetic data analyzed by examining substitutions, distortions, and changes in syllable structure. The results showed that hearing loss significantly affects the stability of air pressure in the oral cavity, the accuracy of the point of articulation, and the consistency of formant transitions to the vowels /a/ and /i/. The most common symptoms include changes from dental consonants to alveolar or velar, vowel modification, nasalization, and the appearance of a glottal stop. These findings highlight that dental sound production requires complex articulatory coordination and relies heavily on auditory feedback. This study is expected to serve as a reference for the development of phonetic-articulatory studies and assist in planning more targeted speech therapy for deaf children.