Less Costly Options for Electronic Devices

By Peter Reitzes, MA CCC-SLP

Altered auditory feedback (AAF) has been used since the 1960s with people who stutter to reduce stuttering behaviors. Currently, the most utilized types of AAF are delayed auditory feedback (DAF) and frequency altered feedback (FAF). DAF and FAF technologies are now available in portable prosthetic devices. The most advanced devices are worn in one ear and are indistinguishable from hearing aids. Prosthetic AAF devices capture the speaker’s speech signal, digitally alter the signal and then re-introduce the altered speech signal into the speaker’s ear.

DAF returns the speech signal to the user’s ear with delay times of varying lengths. The user feels as if he is speaking in unison with himself or speaking in an echo chamber. FAF returns the speech signal with an altered pitch. Many users choose higher pitch settings which return an “Alvin and the Chipmunks” type of voice to the user’s ear. Lower “Darth Vader” sounding pitch settings are used as well.

People who stutter report varying degrees of benefit using portable prosthetic devices. Some report that the devices are helpful and practical across a range of speaking situations; others find that the devices lose some or much of their stuttering-reducing effects over time or are uncomfortable and awkward.

There are multiple theories or beliefs as to why DAF and FAF are able to alleviate and reduce, at least initially, the symptoms of stuttering. One theory is that DAF creates a speaking experience which is similar to speaking in chorus or unison, thus reducing stuttering behaviors.

Additionally, it has been noted by many that DAF slows the speaker’s rate of speech which may account for reduced stuttering.

There are now less expensive options that make use of Bluetooth technology using handheld computers and phones. For $1,600 VoiceAmp offers their Fluency Enhancer device which looks similar to an iPod or other mp3 player. The Fluency Enhancer is digital and its software can be upgraded as AAF technology and options improve.  

The ArtefactSoft software company sells the DAF Assistant for Apple’s iPhone and iPod Touch. This software application includes both DAF and FAF and is available for download for $9.99. ArtefactSoft’s Pocket DAF/FAF Assistant software application (version 2.0) sells for $69.95 and is used with portable devices running Windows Mobile 5.0 operating systems in conjunction with Bluetooth (wireless) headsets.

If you are interested in trying AAF, download free software for DAF and FAF from Rick Arenas’ Web site http://myweb.uiowa.edu/rarenas/index.htm.