Research on Electronic Devices: Preliminary Results

By Anne L. Foundas, M.D., and Edward G. Conture, Ph.D.

From the Stuttering Foundation's Summer 2009 newsletter.

alt textDevelopmental stuttering has a lifetime incidence (i.e., percentage of adults who stuttered at some point) of nearly 5% and is one of the more common developmental speech disorders. Although the disorder significantly impacts the academic, emotional, social and vocational achievements, development and potential of individuals who stutter, important questions remain regarding factors that cause, exacerbate and/or maintain stuttering. Likewise, the efficaciousness of various treatments for stuttering remains a source of vigorous debate as well as investigation. Among such treatments, altered-auditory feedback (AAF) has received considerable attention in recent years.

With advances in digital technology, one such AAF device, the SpeechEasy, has been designed and marketed to treat stuttering. This small device is worn like a hearing aid and can be adjusted in terms of delayed auditory feedback (DAF) as well as frequency altered feedback (FAF) parameters, and volume. According to the SpeechEasy's associated marketing literature, such AAF adjustments of the auditory sidetone for speech mimic the effects of choral reading. Results of empirical studies can be taken to suggest that this device is effective for at least some adults who stutter (AWS; References 1-6).

We have recently initiated an empirical study to characterize, independent of manufacturer specifications, the audiometric (e.g., frequency characteristics) properties of the SpeechEasy as well as its potential influence on stuttering in AWS. Specifically, we have attempted to assess how this device influences stuttering in adults with persistent developmental stuttering (PDS) as well as the extent to which device settings and the use of the device in the left versus the right ear contributes to this influence.

To date, eleven participants (PDS = 7, Controls = 4) have been examined without the device in place (baseline), with the device in place but not on, with the device in place using manufacturer-suggested and manufacturer-independent settings, and in each ear independently. Reading, narrative, and conversational speech-language production were examined for each participant. For this initial study, we limited our sample to right-handed men ages 20 to 40 years who do (PDS) and do not (controls) stutter. Individual performance profiles were examined in relation to baseline output and results were computed as a proportion of utterances (stuttering events in the first 300 syllables in each speaking condition).

Preliminary findings indicate that the device has more influence on stuttering frequency during narration and reading than during conversational speech but that this effect interacts with which ear the device is worn on. That is, some participants exhibited more effect with the device in the left versus right ears. As has been shown with previous studies, there is also considerable variation among participants. The extent to which the placebo effect can account for at least some of these findings is still under investigation.

In summary, our preliminary results appear to indicate that the SpeechEasy device can influence stuttering during at least reading and narration, but that there is considerable individual variation in its effect. It is thought important to determine whether specific settings, ear placement or other biological factors impact users' response to the device. Preliminary findings were taken to suggest that changes in stuttering, at least for some adults who stutter, may be related to changes in speech-language monitoring, something impacted by AAF devices like the Speech Easy. These findings do seem to support the need to further study why this AAF device impacts stuttering for some but not other PDS.

Editor's note: The Stuttering Foundation is pleased to support this new research.

1. Armson J, Kiefte M, Mason J, De Croos D. (2006) The effect of SpeechEasy on stuttering frequency in laboratory conditions. J Fluency Disord. 31:137-152.
2. Armson J, Kiefte M. (2008) The effect of SpeechEasy on stuttering frequency, speech rate, and speech naturalness. J Fluency Disord. 33:120-134.
3. Kalinowski, J. (2003). Self-reported efficacy of an all in-the-ear-canal prosthetic device to inhibit stuttering during one hundred hours of university teaching. Disability and Rehabilitation, 25, 107'111.
4. O'Donnell JJ, Armson J, Kiefte M. (2008) The effectiveness of SpeechEasy during situations of daily living. J Fluency Disord. 2008; 33:99-119.
5. Stuart, A., Kalinowski, J., Rastatter, M. P., Saltuklaroglu, T., & Dayalu, V. (2004). Investigations of the impact of altered auditory feedback in-the ear devices on the speech of people who stutter: Initial fitting and 4-month follow up. International Journal of Language & Communication Disorders, 39, 93'113.
6. Stuart, A, Kalinowski, J, Saltuklaroglu, T, & Guntupalli, VK. (2006). Investigations of the impact of altered auditory feedback in-the-ear devices on the speech of people who stutter: One-year follow-up. Disability and Rehabilitation, 28, 757'765.