What is delayed auditory feedback?
You hear yourself speak through headphones, but a fraction of a second late. That small gap changes how you monitor your own speech, and for many people it has the effect of slowing the rate down and steadying the rhythm. The delay is measured in milliseconds and is adjustable — the optimal delay varies a great deal between people, but you can explore and adjust it until you find the one that suits you.
It has been used in speech therapy for decades. Standalone DAF systems use a microphone and an earpiece or headset to play your voice back after a short delay, usually through a separate processing unit. DAF Pro does the processing on your phone, so no additional hardware unit is needed.
Who does it help?
DAF can help some people who stutter by improving fluency or helping them control their rate of speech. It can also help people with neurological conditions such as Parkinson's, where speech can become fast and unclear: there, DAF can help to slow the speech rate and improve speech clarity.
The effect varies from person to person, so trying different delay settings and speaking situations can help you find out whether it works for you.
Do I need headphones?
Yes. The delayed sound has to reach your ears without the microphone picking it up again, so a speaker will not work. Wired headphones tend to be better than wireless, because Bluetooth adds a delay of its own on top of the one you set.