Stuttering device

Electronic fluency devices (also known as assistive devices, electronic aids, altered auditory feedback devices and altered feedback devices) are electronic devices intended to improve the fluency of persons who stutter. Most electronic fluency devices change the sound of the user's voice in his or her ear.
Types

Electronic fluency devices can be divided into two basic categories.

* Computerized feedback devices provide feedback on the physiological control of respiration and phonation, including loudness, vocal intensity and breathing patterns.

* Altered auditory feedback (AAF) devices alter the speech signal so that speakers hear their voices differently.

Computerized feedback devices

Computerized feedback devices (such as CAFET or Dr. Fluency) use computer technology to increase control over breathing and phonation. A microphone gathers information about the stutterer’s speech and feedback is delivered on a computer screen. Measurements include intensity (loudness), voice quality, breathing patterns, and voicing strategies. These programs are designed to train features related to prolonged speech, a treatment technique which is frequently used in stuttering therapy. No peer-reviewed studies have been published showing the effectiveness of commercial systems in a clinical context. A study of electromyographic (EMG) feedback in children and adolescents found it to be as effective as other treatments (home-based and clinic-based smooth speech training) in the short and longterm.
[edit] Altered auditory feedback devices

Altered auditory feedback (AAF) such as singing, choral speaking, masking, delayed or frequency altered feedback have long been known to reduce stuttering. Early altered auditory feedback devices were large and thus confined to the laboratory or therapy room, but advances in electronics have permitted increasingly portable devices such as Derazne Correctophone, the Edinburgh Masker, the Vocaltech Clinical Vocal Feedback Device, the Fluency Master and the SpeechEasy. Current devices may be similar in size and appearance to a hearing aid, including in-the-ear and completely-in-the-canal models.