Stuttering

The Acoustics of Speech in Individuals who Stutter: Literature

The Acoustics of Speech in Individuals who Stutter
Introduction
Research concerning acoustics in children who stutter, who have recovered from stuttering and adult stutterers shows that there is a lack of coherency in the data collected and reforms need to be made to the methods involved. The research that has been conducted on stuttering pertains mostly to the condition in children; stuttering is most prevalent in younger children and in most cases will be corrected by the later years of youth.
Researchers working within the field are confronted by many problematic factors when both conducting their research and specifically in analysing data. Diverse
Frequency changes and second formant transitions in preschool children who stutter persistently and who have recovered from the condition show general differences in speech patterns between the two groups. Most poignant was the fact that the research showed frequency changes in persistent stutterers were discreet while the recovery group showed marked frequency changes (Subramanian, Yairi, Amir). Research such as this helps to support Yairi’s theory that subtyping may be useful in the field. Along these lines, Armson and Kalinowski pointed out the difficulties in performing acoustic analysis on stutterers when the condition itself may be changing the data. These researchers feel that to properly assess acoustic data they must learn how to separate those factors out which cause stuttering, and which are inherent in individuals only after one has begun to stutter. The acoustics of one individual in a pre-stuttering state might show related frequencies and vowel duration, as well as the
Data were collected in terms both of acoustics and of cerebral blood flow in adults. While females are more likely to recover from stuttering in childhood and males are generally more susceptible to the condition, this research found that the stages of recovery were not significantly different between the gender groups. The researchers concluded that chronic stuttering was related to abnormal speech-motor and auditory region interactions. Healey and Ramig conducted research into stuttering that was specific to treatment, specifically treatment length and its effect on differing severities of the condition. Acoustic analysis of patients undergoing treatment showed that the severity of each case made no significant difference to recovery and the transition from one level to another; similarly treatment time made no difference in the progression and recovery of stutterers. Max and Caruso also explored treatment options, finding that fluency adaptation through the process of repeating specific readings was improved over other methods of treatment. With specific phonological aspects in the readings, designed