Monica Bray, Speech and Language Therapist, reviews research on the use of altered auditory feedback (DAF and FAF) with stammering.

Monica Bray at BSA's Norwich Open Day in 2008.

In the Summer and Autumn 2006 editions of Speaking Out, Heidi King gave her experiences and thoughts on the use of the SpeechEasy device as a means of controlling her stammer, and in Spring 2007, there was a useful review of electronic aids designed to provide information on what was currently available to people who stammer. Also in that issue, Heidi reflected on her growing self awareness and self confidence brought about by a combined speech and language therapy and SpeechEasy approach. So, as we approach Spring 2009, what do we now know about the effectiveness of altered auditory feedback both in terms of reducing stammering and of increasing confidence?

There have been a number of academic articles exploring the amount of stammering reduction and the thoughts and feeling of people trying out feedback devices, and from these there is an emerging picture. It appears that for many, not all, people who stammer the immediate effect of trying out a device may be to reduce the severity of the actual stammer by as much as 85% (Lincoln, Packman and Onslow, 2006). However, these results are often obtained in the clinic and using reading or monologue as a way of gathering the data. Data gathered in more natural settings using conversational speech have rarely been reported. Also, as Armson, Kiefte, Mason, & De Croos, (2006) point out, the response is very variable with some people finding they have a very significant reduction of stammering and others finding very little or none.

In 2008 Pollard, Ellis, Finan and Ramig published a study which followed 11 people using a SpeechEasy device over a period of four months. It appeared that the immediate positive effect on speech fluency was not maintained in all individuals over the four month period. Individuals showed variability in their response to wearing a device with some finding it helpful as a means of enhancing their confidence in speaking while others disliked and felt no positive effect from the device. As in other studies (such as one by Lincoln and Walker, 2006), many individuals chose not to use the device all the time and used it only for certain activities which were anxiety provoking - particularly speaking on the telephone.

In summer 2008 I presented preliminary findings at the Oxford Dysfluency Conference on the use of a prototype Telephone Assistive Device (TAD) produced by VoiceAmp. Nine individuals who stammer agreed to record themselves making both formal and informal telephone calls both before receiving the TAD and with the TAD. The preliminary findings were on six recordings per person before TAD and three per person with TAD for five individuals. A further three recordings per person gathered three/four months after receiving the TAD have more recently been collected and will be reported on at a later date. The group data showed positive trends for both improved fluency and improved confidence when using the phone. As with other studies, there was much individual variation with some people finding the device extremely helpful and others reporting little change overall.

It would appear therefore that the idea of AAF as a "miracle cure" for stammering, as originally reported in the media, is far from the truth. These devices can be useful to some people. They may be useful in reducing stammering or in improving confidence or both. They are less useful in natural situations than in 'laboratory' contexts except possibly for very specific problem areas such as telephone use. Even if 'less' useful, they may of course still be helpful in other natural situations. They may be of benefit when used alongside other therapy techniques. We don't yet know who might be able to benefit most from a device, or in what circumstances or over what period of time. There is still much more to explore and understand before we can unequivocally give support to the use of AAF as a way of ameliorating the symptoms of stammering.

The 2008 ISAD Online Conference includes an article by Pollard and Ellis, with discussion: www.mnsu.edu/comdis/isad11/papers/pollard11.html

References:
Armson, J., Kiefte, M., Mason, J. & De Croos, D.(2006) The effect of SpeechEasy on stuttering frequency in laboratory conditions. Journal of Fluency Disorders, 31, 137-152.
Lincoln, M., Packman, A.,. and Onslow, M.. (2006) Altered auditory feedback and the treatment of stuttering. Journal of Fluency Disorders. 31, 71-89.
Lincoln, M., & Walker, C.. (2007) A survey of Australian adult users of AAF: Use pattern, perceived effectiveness and satisfaction. Disability and Rehabilitation. 29:1-8.
Pollard, R., Ellis, J., Finan, D. & Ramig, P. (2008) Effects of the SpeechEasy on objective and perceived aspects of stuttering: A six-month, Phase I clinical trial in naturalistic environments. Journal of Speech, Language and Hearing Research. published online Aug 11, 2008 as doi:10.1044/1092-4388(2008/07-0204).

Update: Monica's TAD research paper has been published in the International Journal of Speech-Language Pathology (Vol 11 Issue 1) at doi:10.1080/17549500802596263

From the Spring 2009 issue of Speaking Out, page 10.

Information on AAF: www.stammering.org/electronic