Transition deficit in Arabic stuttered speech: an acoustic analysis of word-media geminate consonants

Abstract

Stuttering is a speech disorder that involves frequent and significant problems with normal fluency and flow of speech. People who stutter (PWS) know what they want to say but have difficulty saying it. The disruption in the fluency of verbal expression characterized by involuntary, audible, or silent repetitions or prolongations of sounds or syllables. The current study aimed at answering four questions: identifying the Voice Onset Time (VOT) of those who stutter while speaking Arabic, examining the values of F1 and F2 for all the geminate sounds and their relation to the transition deficit usually noted in the speech of PWS, investigating the role of complex linguistic consonants in the speech of PWS, and understanding how PWS control the temporal compensation between the geminate consonant and the vowel preceding it. Forty Jordanian male native Arabic speakers between the ages of 16 and 50 years old were recruited. The subjects were divided into two groups comprising PWS and fluent speakers (FP). Data was collected in a quiet room at the speech therapy clinic of the King Abdullah the second Hospital. Once seated, participants were asked to produce each of the minimal pairs /bata/, /batta/ and /bada/, /badda/ three times and was recorded using a Sony ICD Mono Digital Voice Recorder. All speech productions were recorded and analyzed acoustically using the PRAAT software and analyzed statistically using SPSS. Results revealed significant differences between PWS and the FP group regarding their VOT, F1, F2, target consonant duration and previous vowel duration. In comparison to the FP group, the VOT values for geminates /tt/ and /dd/ were 4 and 2.5 times longer, respectively, in PWS. The vowel preceding the target consonant is longer in the vicinity of the singleton and is shortened preceding a geminate. The degree of shortening is significantly different within FP and PWS. The result of the current study delineates the effect of geminates and has implications for speech therapy management of PWS.