Delayed Auditory Feedback (DAF) is a auditory feedback technique used in a variety of speech and language therapy settings. DAF works by extending the time between speech and auditory perception, creating a "chorus effect" around a speaker's voice and slowing the rate of speech for a speaker. Research has shown the DAF can be an effective method for inducing higher rates of fluency for people who stutter.
Delayed auditory feedback has been used effectively to support fluency for stuttering and those with Parkinson's, however it should not be used as a tool for fluent speakers as it may disrupt their speaking patterns. In practice, DAF is a simple process that delays when a user hears his or her voice through headphones at a fraction of a second after speakig into a microphone.
There are many tools that provide delayed auditory feedback options, including hardware devices with headphones and hearing aide-like devices. Increasingly, these technologies are being made available digitally through a speech therapy app like Speech4Good.
In the following sections, we will describe how SLPs have successfully used Speech4Good, an app created by a person who stutters to help users access this DAF technology on-the-go at any time to support fluency.
In the Speech4Good app, users can select from a range of adjustable delays—from 20-300 milliseconds. With headphones on, the app will automatically produce delayed auditory feedback, creating a chorus effect for users as they speak in real-time. Users can use any type of headphones to connect to the app, but we recommend using Apple's standard earbuds with a remote microphone to create the best experience.
While speaking with delayed auditory feedback engaged, users can also open another app—such as reading from a browser or flashcards—while the DAF feature is still engaged while using the background audio feature. This way, SLPs can have students read from a news article or other source while practicing their voicing with DAF.
Speech4Good also offers a Bluetooth and Airplay option so users can connect to the app using a wireless headset or headphones. This allows users to keep their iPhone device in their pocket will speaking with DAF on through their headphones.
The app also includes a variety of other features, including a visual speech graph that shows variations in speech volume in real-time, as well as recording and note-taking features to save your speech therapy practice files and track progress over time.
"The option for Delayed Auditory Feedback really sets the app apart. It’s adjustable on the right hand side. You can record speech samples up to 10 minutes in length. I used the DAF for fluency students. The voice recording works for kids with articulation and expressive language treatment as well!" -Speech Room News
"Treatment Using the Speech4Good Application: Plug headphones with a microphone into the iPhone to use the Delayed Auditory Feedback (DAF) function. Determine the length of delay to use with the client. Have the client practice his or her fluency modification or fluency strategies at home and e-mail you the files of his or her recordings to keep a record." -Speech Techie
"I love the fact that this application includes visual feedback. This is great for students who are working on voice, fluency strategies, and articulation by viewing the length and amplification of a syllable/phoneme, length and amplification of a disfluency, change in amplification when using a fluency shaping/modification strategy, and amplication of the voice. It is also motivating for students/clients." -Consonantly Speaking