The Acoustics of Speech in Individuals who Stutter
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 methods of data
compilation and independent methods of interpretation mean that what one scientists concludes from an experiment may not support established theories and existing information on the subject. It can be assumed that analysis of acoustics in stuttering needs to be done with a specific framework that all researchers can work from. Issues like the diagnosis of stuttering complexes from mild, moderate and severe; the focus on frequency changes; and subtyping have all been encountered and brought up for review by researchers who wish to have a more fully rounded database from which to study stuttering in all its forms. A review of literature on the subject exposes many difficulties within the field of research and offers suggestions on how these might be addressed and overcome. Once a basic premise for observation, study and analysis is reached, the database will be much more comprehensive and useful to future research.
Acoustic analysis is the foundation to stuttering research conducted by many different scientists and scholars; the ways in which this research is conducted vary, however, and therefore can produce subsequently varied results and different ways of looking at stuttering itself. Some researchers are of the opinion that stuttering is heavily influenced by the actual perception of listeners, and that though analysis of reaction and perception of acoustics in stutterers it is possible to more fully comprehend those characteristics of speech that are a part of the disorder (Amir, Yairi). Through analysis of speech patterns in preschool aged children, the researchers concluded that interval duration in speech patterns must exceed 70 ms to be considered normal speech; under 50 ms interval duration was therefore attributed to stutterers.
Some researchers have taken acoustic analysis to a new level with the use of the computer as a more failsafe analytical tool; due to a lack of specific acoustic parameters by which to
classify stuttering the computer offers a more solid foundation for diagnosis and treatment (Brosch, Hage, Johannsen). Research conducted by these authors was inconclusive because of a lack of cohesive data on the subject, however it is their belief that with further study one might better understand the correlations between specific acoustics and the different stages of
stuttering. The primary factor thought to be attributed to stuttering in different stages is age.
Chang, Ohde and Conture believe that it is a disorganization of specific factors of speech, in particular the transition rate of speech formation, that can be cited as a precursor to
stuttering. This research is key to the development of
stuttering studies because currently there are very little data or theoretical models to explain the conditions that lead to stuttering in children. Through acoustic analysis not only of children and adults who currently stutter, but the acoustic analysis of children who will later develop a stutter, these researchers believe that more will be understood about the
progression of the disorder and subsequently the treatment
Given the generalities of...