DAF Pro: Stuttering,Stammering 4+

Speech therapy aid for fluency

Speechtools Ltd

Designed for iPad

    • £2.99



* The world's number 1 DAF app is used by thousands of people in over one hundred countries. *

DAF Professional has been created to help people who stammer or have a neurological disease such as Parkinson's Disease. It helps people to slow their rate of speech which makes it clearer to others.

DAF Professional is an easy to use professional speech therapy tool which could make a huge difference to you or someone you know.

DAF Professional has been designed and tested by a certified and practicing Speech and Language Therapist (MSc, PGDip, BAHons, HPC registered and member of RCSLT). DAF Professional delivers incredibly low latency feedback even when running in the background.

Delayed Auditory Feedback (DAF) is a well established speech and language therapy tool which helps people to speak more slowly. However, until recently, devices have been cumbersome to carry around, difficult to adjust, very expensive and therefore not widely used.

DAF was originally developed for people who stammer, but has since been shown to work with people with other speech difficulties, such as those with Parkinson's Disease (Downie et al., 1981; Dagenaise, Outhwood & Lee, 1998; Lowit et al., 2006 and most recentely Lowit et al., 2010).

It works by enabling someone to hear his or her own speech in an altered manner. This disruption to the normal auditory feedback loop causes the speaker to slow down. Research has shown that DAF will be of benefit to approximately a third of people who have a stammer or Parkinson's. Clinical research has not been carried out as yet on other client groups however DAF may well be of benefit to people with other medical speech conditions.

When using Bluetooth devices there is an additional delay of 60ms added to the feedback system.

If you do use a Bluetooth headset you may find you need to turn the bluetooth device on after opening the app to enable it.

DAF Professional works when put in the background or the screen is turned off. Like all apps of this type, it can NOT work during phone calls or with other media apps playing at the same time.

If you wish to provide any feedback we would be delighted to hear from you. Please email us at support@speechtools.co.

Our lead Speech and Language Therapist is Samantha Brady who qualified as a Speech and Language Therapist in 2001 (PGDip, City University) and gained her Masters in Speech and Language Therapy in 2006 (MSc, City University). She has a wealth of experience of working as a Speech and Language Therapist in a variety of settings and her area of clinical expertise is adult neurology and voice. Samantha is a member of the Royal College of Speech and Language Therapists (RCSLT), HPC Registered (SL10250) and Lee Silverman Voice Treatment Certified (LSVT).

DAF Professional is fully GDPR compliant and will not collect any of your data without first asking for your consent.

What’s New

Version 3.5.0

Bug fixes and minor improvements

Ratings and Reviews

4.2 out of 5
5 Ratings

5 Ratings

Original Fembot ,

Slow speech down

This has helped me massively to slow my speech down and reduce anxiety when speaking in public and with clients on the phone. It's helped make myself clearly understood. It also helps me manage my breathing which makes me appear more confident and assured. Excellent product

LisaMcOT ,

Fantastic app

Finding this app really useful and easy to use. Have contacted the developers and always had prompt replies with friendly information. Cant recommend highly enough. Download this app .

Metboyfg ,


Great app , worked perfectly. I'm an adult stutterer and have biggest blocks on phone calls. Although app doesn't work when taking phone calls on iPhone, I use it when on land line with one ear on speaker buds - really increased my fluency

App Privacy

The developer, Speechtools Ltd, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • Usage Data
  • Diagnostics

Privacy practices may vary based on, for example, the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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