Glottal Characteristics of People who Stutter and the Interaction with Syllable Complexity

Stuttering is characterized by respiratory, laryngeal and articulatory peculiarities, especially when the to-be-produced speech is complex. This study examined the glottal behaviour in people who stutter (PWS) during production of simple bilabial (/p/, /b/, /m/) and complex (/pR/, /bR/) onsets. It was hypothesized that the glottal behavior of PWS presented idiosyncrasies, compared to people who do not stutter (PNS) and that these were modulated by the complexity of the onset. Producing semi-spontaneous speech with embedded target words, acoustic and EGG data were collected from 4 PWS and 4 PNS. From the perceptually fluent productions, duration of bilabial occlusion, intensity, open quotient (OQ), difference in intensity, pitch and laryngeal OQ between occlusion-phase and following vowel were measured. No significant differences in glottal behavior were found between PWS and PNS. However, compared to PNS, PWS devoiced voiced consonants significantly more, which motivates a larger-scale investigation with more participants.