Electronic fluency device

[1] These programs are designed to train features related to prolonged speech, a treatment technique which is frequently used in stuttering therapy.

[3] 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.

[8] Current devices may be similar in size and appearance to a hearing aid, including in-the-ear and completely-in-the-canal models.

Varying pitch from quarter, half or full octave shift typically results in 55–74% decreases stuttering in short reading tasks.

[24] In studies that gave longer exposure to FAF and used more meaningful daily life tasks such as generating a monologue, only some participants experienced a reduction in stuttering.

[21] In the last years a number of smart phone apps have been developed that implement DAF/FAF as software and are much cheaper than the special hardware devices.

[9][25] However, the effects of altered feedback are highly individualistic, with some obtaining considerable increases in fluency, while others receive little or no benefit.

[30] In addition, studies have been critiqued for failing to demonstrate ecological validity; in particular that AAF effects continue over the long term and in everyday speaking situations.

[8][18][31] The high-profile promotion in the media of devices such as the "SpeechEasy" has been criticized as inappropriate given the lack of scientific evidence for their effectiveness.

[2] Several studies have produced group results that stutterers using the SpeechEasy show greater reductions in reading than for monologue and conversation.

[39] Given the lack of evidence of its effectiveness, as well as concerns about the impact of altered feedback on developing speech and language systems, some authors have expressed the view that the use of an AAF with children would be unethical.

[41][42] Some suggest that stuttering is caused by defective auditory processing, and that AAF helps to correct the misperceived rhythmic structure of speech.