# DAF Pro: Stutter & Parkinson's — Delayed auditory feedback

> Speech therapy app using Delayed Auditory Feedback for stuttering and stammering. (iPhone/iPad app by Speechtools Ltd.)

- Source: https://appshunter.io/ios/app/daf-pro-stutter-and-parkinsons/id491299921 (this page in markdown: same URL + `.md`)
- Developer: [Speechtools Ltd](https://appshunter.io/developer/940679564)
- Category: Medical, Utilities
- Price: $5.99
- Rating: 4.50/5 from 97 App Store ratings · 51 written reviews indexed
- Age rating: 4+
- Requires: iOS 17.0 · 12 MB
- Languages: Russian, Hindi, Vietnamese, American English, Arabic, Dutch, Greek, Danish, Hebrew, Indonesian and 16 more
- Released: 2012-01-04
- Data updated: 2026-09-16
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/daf-pro-stutter-and-parkinsons/id491299921/reviews.md

## What is DAF Pro?

DAF Pro helps people who stutter and people with Parkinson's slow down and speak more fluently. Put on headphones, speak, and hear your own voice a fraction of a second later.

How It Works
Delayed auditory feedback (DAF) 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 control their speaking rate.

Who It's For
* 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
* Adjustable delay and pitch shift
* Very low latency, so short delays stay short
* Keeps working in the background and with the screen off
* Record and play back your speech
* Works with wired and Bluetooth headsets. Bluetooth adds extra delay that varies by headset, so wired headphones work best for short delays.

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.

Built by a UK speech and language therapist. One-time purchase: no subscription, no ads, no account needed.

Questions or feedback? Contact us at support@speechtools.co

## Key features

- Delayed Auditory Feedback (DAF)
- Real-time audio feedback
- Works in background/screen off
- Developed by certified therapist
- Supports wired & Bluetooth headsets
- No ads or data collection

## Chart rankings

- #32 in Top Paid · Medical (US App Store)

## Recent user reviews (10 of 51)

All indexed reviews: https://appshunter.io/ios/app/daf-pro-stutter-and-parkinsons/id491299921/reviews.md

### 3/5 — Pas de conseil

*2026-04-22*

Pas de conseils ou feed back, c’est dommage, il s’agit juste d’enregistrer et écouter en temps réel sa voix

**Developer response:** Merci d'avoir essayé l'application ! Le DAF (Delayed Auditory Feedback, ou retour auditif retardé) est une technique de thérapie de la parole bien précise : l'application vous renvoie volontairement votre voix avec un léger décalage, et ce décalage est lui-même le mécanisme thérapeutique. Il est principalement utilisé pour le bégaiement, les troubles de la fluidité, ainsi que les difficultés d'élocution liées à certaines pathologies comme la maladie de Parkinson. Ce n'est donc pas une application de coaching avec des conseils ou des astuces — le bénéfice vient du fait de parler tout en entendant ce retour retardé. Si vous souhaitez en savoir plus pour bien l'utiliser, n'hésitez pas à me contacter via l'e-mail de support dans l'application.

### 1/5 — マイクが切れる

*2026-03-21*

本日購入して使用しましたが、しばらくするとマイクが切れました。1から2分後です。練習に使いたいのでこれでは使えません。修正してください。

**Developer response:** この度はアプリをご購入いただき、誠にありがとうございます。マイクが1〜2分ほどで切れてしまうとのこと、ご不便をおかけし大変申し訳ございません。通常起こる症状ではございませんので、できるだけ早く修正させていただきたく存じます。
お手数をおかけしますが、アプリ内のサポートメニューより、ご使用の端末モデル、iOSのバージョン、および有線イヤホン／Bluetoothイヤホンのいずれをご使用かをお知らせいただけますでしょうか。原因を特定し、修正版をできるだけ早くご提供いたします。
ご報告いただきありがとうございました。

### 4/5 — 不知道为什么听录音每次短句的最后一个声音都一会大一会小的

*2026-01-27*

不知道为什么听录音每次短句的声音都一下大一下小的

### 1/5 — 别下载，骗子软件

*2025-10-21*

也不知道这个评论能不能被看到，比较十三个评论就显示了三个，功能完全不能用，就是个摆设，苹果那边也不给退费，买了就只能被气死。千万别买，拿口吃圈钱的简直不得耗si

**Developer response:** 您好，很抱歉您遇到了一些问题。请发送电子邮件至 support@speechtools.co 联系我们，我们很乐意为您提供帮助，并向您证明我们绝非诈骗。

### 5/5 — Life Saver

*2025-09-10*

This app has been a life saver. I cannot recall the last time I have ever felt more confident going into meetings. Little to no stammering, only have to gather my thoughts before I speak. Thank you to whoever developed this app. I plug in one ear piece to listen during meetings.

**Developer response:** That's great to hear, so glad we've been able to help.

### 2/5 — マイク

*2025-07-20*

数分したら、マイクが切れてしまいます。

**Developer response:** こんにちは。問題は解決しました。ご不便をおかけして申し訳ございません。何かご不明な点がございましたら、support@speechtools.co までご連絡ください。

### 5/5 — Great app

*2025-05-31*

Great app

**Developer response:** Thanks!

### 4/5 — Issue with Audio Feedback in the "Voice Stabilizer" App

*2025-03-08*

Hello! Thank you for your "Voice Stabilizer" app—it truly helps with speech practice. However, I encountered an issue: the audio feedback function automatically shuts off after 60 seconds, especially when the app is running in the background. This significantly disrupts the ability to use the app for extended periods without needing to reopen it and restart the function. It would be great if you could add an option for continuous audio feedback, even when the app is minimized, or provide a setting to adjust the duration of this feature. This enhancement would greatly improve the user experience and the effectiveness of the training sessions. Thank you in advance for addressing this issue. I look forward to future updates!

**Developer response:** Hi, we've fixed that now and if there's anything else we can do to help please get in contact at support@speechtools.co.

### 4/5 — 版本更新以后，开降噪直接没声音

*2025-03-05*

版本更新以后，开降噪直接没声音，望改进

**Developer response:** 您好，请降低“背景噪音消除”的音量，这样您就能听到自己的声音，但听不到背景声音。

### 2/5 — Noise

*2024-12-18*

Ripple noise while I’m speaking. Unusable, I’m going to get a refund.

## Frequently asked questions about DAF Pro

### What is DAF Pro and how does it help with speech?

DAF Pro is a speech therapy application that utilizes Delayed Auditory Feedback (DAF). This technique alters how you hear your own voice, prompting your brain to naturally slow down your speaking rate. This can lead to clearer, more fluent speech, and is beneficial for individuals who stammer or have conditions like Parkinson's Disease.

### What are the key features of DAF Pro?

Key features include the use of clinically recognized DAF for speech therapy, ultra-low latency for real-time feedback, and an easy-to-use interface. It also works when the screen is off, supports various headsets, and is GDPR compliant with no ads or data collection.

### How much does DAF Pro cost?

Based on the provided information, DAF Pro is a paid application. There are no mentions of in-app purchases or subscription models, indicating a one-time purchase for access to its features.

### What devices is DAF Pro compatible with?

DAF Pro is designed for mobile use and supports both wired and Bluetooth headsets. While it functions with Bluetooth, users should be aware that it may introduce a slight delay of approximately 60ms. The app is also designed to work effectively even when the device's screen is turned off.

### Who developed DAF Pro and is it a reliable tool?

DAF Pro was developed and tested by a certified Speech & Language Therapist, making it a trusted professional tool. Its effectiveness is supported by research showing benefits for individuals with stammers or Parkinson's, and it is used worldwide as a leading DAF application.

## Version history (last 5 releases)

### 4.9.5 — 2026-09-15

* Fixed a crash that could occur when playing back a recording.
* DAF now starts reliably after a phone call or a change of headphones.
* Fixed audio stuttering when switching headphones during a recording.

### 4.9.4 — 2026-09-02

* Fixed a crash that could occur when playing back a recording.
* DAF now starts reliably after a phone call or a change of headphones.
* Fixed audio stuttering when switching headphones during a recording.

### 4.9.3 — 2026-08-11

Bug fixes and performance enhancements

### 4.9.2 — 2026-08-08

Bug fixes and performance enhancements

### 4.9.1 — 2026-05-13

Bug fixes and performance enhancements

## Apps similar to DAF Pro

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Speech Sounds Visualized](https://appshunter.io/ios/app/speech-sounds-visualized/id1300151606) | 4.3 (131) | Free | Medical |
| [Speech Therapy Articulation UK](https://appshunter.io/ios/app/speech-therapy-articulation-uk/id6449045838) | 4.0 (1) | Free | Medical |

## More apps by Speechtools Ltd

- [Swallow Prompt: Saliva Help](https://appshunter.io/ios/app/swallow-prompt-saliva-help/id574942154)
- [Voice Analyst: Pitch & Volume](https://appshunter.io/ios/app/voice-analyst-pitch-and-volume/id732245213)
- [Christella VoiceUp: MTF Voice](https://appshunter.io/ios/app/christella-voiceup-mtf-voice/id1124464717)
- [One Minute Voice WarmUp](https://appshunter.io/ios/app/one-minute-voice-warmup/id1212802251)
- [Christella VoiceUp Complete](https://appshunter.io/ios/app/christella-voiceup-complete/id1471610662)

All apps by Speechtools Ltd: https://appshunter.io/developer/940679564

## Related topics

[delayed auditory feedback](https://appshunter.io/ios/topics/delayed-auditory-feedback) · [daf delayed auditory feedback](https://appshunter.io/ios/topics/daf-delayed-auditory-feedback)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-16.*