DAF Delayed Auditory Feedback1.2.2 - App Store

Try saying "toy boat" repeatedly.
It's hard to say, right? There are many words like this, and if you have to use them during an important presentation, it can be quite stressful.

But with this app, "toy boat" becomes...
**Hugely** difficult to say.
If you thought, "Wait, shouldn't it make it easier to say?" you're wrong. It really becomes **hugely** difficult to say. This is a "who benefits from this?" kind of app.

What this app does is simple. It picks up your voice through the microphone and plays it back through the headphones (or earphones) with a slight delay. That's all it does.
This simple process is called Delayed Auditory Feedback, or DAF for short.

DAF is known to have interesting effects.
It makes it difficult to speak. So, the already difficult "toy boat" becomes **hugely** difficult to say with DAF.

This might seem like a "who benefits from this?" kind of thing, but it's a very interesting phenomenon from a cognitive psychology perspective.
Also, DAF doesn't always make speech difficult; the extent of the disruption varies depending on the amount of delay and the way you speak.
This app is a simple psychological experiment tool that allows you to test when DAF's effects are most pronounced using yourself as the subject.
Experiment with different scenarios using "toy boat" as the keyword.

**Important** When using this app, you must have headphones (or earphones) with a microphone. You cannot substitute the device's built-in microphone and speakers.

I'll say it again.

You cannot substitute the device's built-in microphone and speakers.

**Warning** DAF creates a speech situation different from normal. It is possible that this may cause some stress to your mind and body. We cannot take any responsibility for any issues that arise from using this app. Please understand the principles of DAF fully and use this app at your own risk. If you feel any abnormalities in your mind or body, stop using the app immediately. Additionally, we do not recommend letting minors, especially young children, experience DAF.

**Effect on Stuttering** There are reports that DAF has improved stuttering. However, this app was developed purely as a simple psychological experiment tool to examine how DAF affects the speech of non-stutterers from a cognitive psychology perspective.

Version History Minor fixes. 1.2.2 12/14/2025 You can now experience DAF not only with wired earphones, but also with bluetooth headsets. 1.2.1 07/11/2024 (1) The app icon was changed.
(2) Microphone sensitivity can now be adjusted. 1.2.0 06/20/2024 Rebuilt using newest SDK for improving stability. 1.1.9 05/14/2019 Minor fixes to improve stability. 1.1.8 12/18/2018 The app checks iPhone's mic settings more strictly. 1.1.7 10/10/2018 Now the app supports iOS 11.0 and later. 1.1.6 10/01/2018 Minor fixes to improve stability (built with new SDK). 1.1.5 08/30/2018 Built the app using a new SDK. 1.1.4 02/26/2018 Minor fixes for stability. 1.1.3 01/05/2017 Minor fixes. 1.1.2 01/03/2017 Minor bugfixes. 1.1.1 06/01/2015 * English instruction
* iOS8 support
* Multiscreen support 1.1.0 11/23/2014 A very minor fix to the instruction text.
解説文にわずかながら修正を加えました。 1.0.1 06/19/2013 1.0.0 03/12/2013