Delayed Auditory Feedback (DAF) and Stuttering: Enhancing Fluency Through Technology
Delayed Auditory Feedback (DAF) is a scientifically backed method used in speech therapy that plays a speaker’s voice back with a short delay. It has been shown to induce fluency in many individuals who stutter.
Understanding Delayed Auditory Feedback
When you speak, your brain expects to hear your voice immediately. DAF introduces a delay (e.g., 20-200 milliseconds), which disrupts the feedback loop and causes the speaker to unconsciously slow down or modify their speech pattern. This tool uses your browser’s microphone to capture your voice, then plays it back with a customizable delay.
Delayed auditory feedback is reported to stimulate the area in our brains responsible for processing sound information. Additionally, DAF was found to reduce overactivity in the speech motor control area of the brain and decrease extraneous muscle movement when speaking.
Benefits of DAF in Speech Therapy
- Enhance fluency by applying techniques learned in speech therapy.
- Increase the individual’s awareness of their stutter.
- Improve their self-monitoring skills.
Speech-language pathologists evaluate and treat individuals who stutter. A few fluency strategies taught in fluency therapy are slow/easy speech, easy onsets, deep breathing, and strategic pausing. SLPs may also use auditory (hearing) feedback tools to improve a person’s fluency.
How to Use DAF Effectively
Using the Delayed Auditory Feedback (DAF) tool is simple:
- Adjust the delay time: Move the delay slider to adjust the feedback delay.
- Practice speaking: Once activated, speak into the microphone.
- Practice using DAF in high-stress talking situations to meaningfully practice the implementation/use of the device.
Important Note: Avoid Bluetooth headphones - they add extra delay that disrupts DAF effectiveness.
Research on DAF and Stuttering
Researchers have identified a subset of stutterers that may benefit most from delayed auditory feedback (a technique by which the original acoustic speech signal is artificially modified and then fed back via headphones). However, not all stutterers experience enhanced fluency by this technique.
A study group of 14 adults with this type of stuttering disorder and 14 control subjects read prose passages three times: at baseline, with non-altered feedback, and with DAF. "We found a subgroup of adults with atypical rightward planum temporale asymmetry, who were more disfluent at baseline and had fluency induced with DAF," noted study author Anne Foundas, MD, of Tulane University in New Orleans, LA.
The primary aim of this study was to learn if there is a relationship between the anatomy of the auditory association cortex (planum temporale) and fluency induced with DAF in adults with persistent developmental stuttering.
Brain Areas Involved in Speech Production
DAF Online Tool
Our DAF Online Tool lets you experience this technique instantly in your browser, with no downloads or installations required. This tool uses your browser’s microphone to capture your voice, then plays it back with a customizable delay. No installation is needed. Yes! Give it a go!
Testimonials
Here's what people are saying about DAF:
- “This tool helped me slow down and speak more clearly."
- “As a speech therapist, I recommend this to clients who need at-home fluency practice.” - Dr. L.