The Use of Daf in Stuttering Therapy

Abstract

A BRIEF review of the research on delayed auditory feedback would appear tv be appropriate before proceeding to describe its utility in stuttering therapy. As now we know well, when a speaker's speech is'returned to his ears a fraction of a second after the time it normally would arrive, certain changes in his speech occur. His verbal output tends to be slowed down (Black, 1951); repetitions of syllables and prolongations of sounds are observed (Lee, 1951); the speech becomes slurred and certain sounds are distorted or omitted (Ham and Steer, 1967). The artificial stutter and the articulation errors were viewed by Fairbanks and Gunman (1958) as the primary behaviours produced by the delay. However, according to these authors, the other behaviors such as an increase in the pitch of the voice and an increase in vocal intensity together with pauses, palmar sweating and flushing were seen as reactions to the experience.It should be mentioned that there exists a wide individual variability in all these reactions, whether primary or secondary (Beaumont and FOSS, 1957). Some individuals indeed seem to be relatively unaffected by DAF : other persons show a proclivity toward repetitions while others prolong their vowels. Some react with marked pitch changes or increases in loudness; a few even demonstrate difficulty in word finding (Meyer-Epler and Luchsinger, 1965). Males seem more vulnerable than females (Bachrach, 1964). Chase and his co-workers (1961) reported that older children and adults are more affected than the younger ones but other recent research by MacKay (1968) does not substantiate this. Adaptation to DAF can be achieved, despite some of the earlier research (Atkinson, 1953 and Neelley, 1956)~ but usually only after prolonged exposure (Goldiamond, 1965;Winchester, Gibbons and Krebs, 1959). Some lingering effects in terms of disrupted speech has been reported by Black (1955) and others but these seem to be transient.The question has been posed as to whether or not the repetitions and prolongations shown under DAF are similar or identical with stuttering behaviors. Neelley's (1961) research seemed to indicate that they were not; however, Yates (1963) and others have criticized the design of his study and especially his conclusions.A rather surprising finding is that certain stutterers (Soderberg, 1969)~ especially the more severe ones, speak much better under DAF than under normal feedback conditions. Chase (1958) reported that children who showed more repetitions in their speech than normal improved in fluency under DAF. Nessel (1958) in Germany found that some stutterers spoke better under DAF; so also did Lotzman (1961) who studied 60 stutterers and used a variety of delay times. Adamzcyk (1963) in Poland, Bohr (1963) in South Africa, Zerneri (1965 in Italy, and a number of workers in the United States have demonstrated that certain stutterers speak much more fluently under DAF. A very interesting study was done by Cohen and Richards (1965). They attempted to interfere with the stutterer's presumed...

Overcoming Stuttering Using Delayed Auditory Feedback (DAF): A Case Study

“…In fact, as have been discussed earlier, many neuropsychologists and(SLP/Ts) recommend DAF as a crucial solution for stutterers that will definitely help them ameliorate their stuttering (Soderberg, 1969;Wingate,1970, Van Riper, 1970,1978Bloodstein, 1981;Byrne, 1983).…”

THE TREATMENT OF STAMMERING BY THE INTENSIVE PRACTICE OF FLUENT SPEECH1

“…This in turn would make it unnecessary to try to construct a portable D.A.F. apparatus (Van Riper, 1970) in order to obtain a generalization of the effect. The stammerer could simulate the effects of D.A.F.…”

“…was used in the first session and at the beginning of some later sessions in order to establish fluency. The subjects were given instructions to speak slowly with elongated vowels, and the volume and delay most conducive to fluent speech were selected (Van Riper 1970). If a subject stammered while not using the apparatus, he was asked to return to it and give a short monologue.…”

Cortical and subcortical mechanisms of persistent stuttering

“…Fluency is reliably enhanced when speech is timed to a pacer: either an external pacer such as a rhythmic beat (Wingate, 2002;Wohl, 1968), the unison speaking with another person (Adams and Ramig, 1980;Ingham and Carroll, 1977;Saltuklaroglu et al, 2009), or an internal pacer such as rhythmic arm swinging or a finger tapping . Alternative fluency enhancing techniques are delayed or frequency shifted auditory feedback (Antipova et al, 2008;Van Riper, 1970).…”