Impact of the Telephone Assistive Device (TAD) on stuttering severity while speaking on the telephone

Nola Chambers

doi:10.4102/sajcd.v56i1.190

Abstract

There is extensive experimental evidence that altered auditory feedback (AAF) can have a clinically significant effect on the severity of speech symptoms in people who stutter. However, there is less evidence regarding whether these experimental effects can be observed in naturalistic everyday settings particularly when using the telephone. This study aimed to investigate the effectiveness of the Telephone Assistive Device (TAD), which is designed to provide AAF on the telephone to people who stutter, on reducing stuttering severity. Nine adults participated in a quasi-experimental study. Stuttering severity was measured first without and then with the device in participants' naturalistic settings while making and receiving telephone calls (immediate benefit). Participants were then allowed a week of repeated use of the device following which all measurements were repeated (delayed benefit). Overall, results revealed significant immediate benefits from the TAD in all call conditions. Delayed benefits in received and total calls were also significant. There was substantial individual variability in response to the TAD but none of the demographic or speech-related factors measured in the study were found to significantly impact the benefit (immediate or delayed) derived from the TAD. Results have implications for clinical decision making for adults who stutter.

Highlights

There is extensive experimental evidence that altered auditory feedback (AAF) can have a clinically significant effect on the severity of speech symptoms in people who stutter
The extent of benefit derived from the Tele phone Assistive Device® (TAD) appeared to bear no rela tionship with initial severity of stuttering, predominance of silent blocks, use of first or second language on the telephone, or level of restriction in telephone use reported by the participants at the start of the study
This complicates clinical decision making in the assessment of individual clients and in attempting to make prog noses as to who might benefit from the device

Summary

Introduction

There is extensive experimental evidence that altered auditory feedback (AAF) can have a clinically significant effect on the severity of speech symptoms in people who stutter. More recent theories have attributed the effects of AAF to reducing auditory perceptual anomalies in those who stutter, related to anatomical anomalies of the auditory temporal cortex (i.e., atypical rightward asymmetry of the planum temporale (PT); Foundas et al, 2004) Based on their physiological findings, Foundas and colleagues have proposed two subgroups within the stuttering population, those with typical (leftward) PT asymmetry, which they consider adaptive and may respond to motor speech techniques alone, and those with atypical (rightward) PT asymmetry, which is a significant risk factor for developmental stuttering, which may be more responsive to treatment via AAF as demonstrated in their study. Armson et al (2006) found greater benefits from AAF in formulated speech (i.e., not reading) in adults with mild stuttering compared to those with more severe stuttering at baseline

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