DAF Pro: Stutter & Parkinson's

DAF Pro uses delayed auditory feedback (DAF) to help people who stutter and people with Parkinson's disease slow down and speak more fluently. You speak, and hear your own voice through headphones a fraction of a second later. DAF Pro is not a medical device.

Built by a UK speech and language therapist (MSc, PGDip, BA Hons, HCPC registered, RCSLT member), and used by thousands of people in more than 100 countries.

What is delayed auditory feedback?

Delayed auditory feedback is a clinically recognized speech therapy technique. Hearing your voice on a short delay naturally slows your speaking rate, which can make speech smoother and clearer. Research suggests DAF helps around 1 in 3 people who stutter, and it is also used to help people with Parkinson's disease control their speaking rate.

Who uses DAF Pro?

• People who stutter or stammer

• People with Parkinson's disease

• People with dysarthria

• People who clutter

• Speech-language pathologists, for therapy sessions and home practice

Features

✓ Very low latency, so short delays stay short

✓ Adjustable delay and pitch shift

✓ Background mode: keeps working while you use other apps

✓ Microphone boost and background noise reduction

✓ Record and play back your speech

✓ Wired and Bluetooth headsets. Bluetooth adds extra delay that varies by headset, so wired headphones work best for short delays.

✓ No ads, no account needed, works offline

Everyday uses

• Daily fluency practice at home

• Reading aloud and preparing for presentations

• Practicing between speech therapy sessions

Getting started

Put on headphones, set the delay to around 50–100 ms, press Start and speak. Then adjust until your speech feels slower and steadier.

Need support? Contact us at support@speechtools.co