Investigation of velopharyngeal motion during speech while producing different sounds through magnetic resonance imaging

The motion of the articulators may vary according to the production characteristics of speech sounds and the coarticulatory context. The motion of the velum, which is a mobile articulator, is also expected to be affected by the production characteristics of speech sounds and the coarticulatory context. In our study, magnetic resonance images (MRI) of 20 healthy adult individuals whose native language is Turkish, were analyzed in the midsagittal plane in order to investigate the velum motion in different sound productions. The measurements were done at rest position, isolated production of /a/, /i/, /e/, /o/, /u/ and during the production of vowels in the consonant-vowel context with a stop/plosive (/b/, /d/, /g/), fricate (/z/), affricate (/dʒ/), nasal (/m/, /n/), lateral (/l/), flap (/r/). By means of the measurements performed, it was aimed to compare the velar elevation, the bending angle of the velum, the distance of the velar angulation from the beginning of the velum and the distance between the nasal surface of the velum and the posterior pharyngeal wall. According to the findings of our study, the motion characteristics of the velum in Turkish speaking healthy adult individuals vary in the production of different speech sounds. The motion characteristics of the velum change in isolated vowel productions or in vowels produced in different consonant contexts. Magnetic resonance imaging is thought to be an appropriate and advantageous method to reveal these changes. In future research, there is a need for more studies investigating velopharyngeal port motion through magnetic resonance imaging.