# DAF Delayed Auditory Feedback — Speech Jammer > Delayed auditory feedback tool for speech disruption experiments. (iPhone/iPad app by Junichiro Seyama.) - Source: https://appshunter.io/ios/app/daf-delayed-auditory-feedback/id606979390 (this page in markdown: same URL + `.md`) - Developer: [Junichiro Seyama](https://appshunter.io/developer/537815782) - Category: Entertainment, Health & Fitness - Price: Free - Rating: 2.30/5 from 6 App Store ratings · 10 written reviews indexed - Age rating: 12+ - Requires: iOS 15.0 · 5 MB - Languages: American English, Japanese - Released: 2013-03-12 - Data updated: 2026-08-19 - Monetization: ad-supported - User reviews in markdown: https://appshunter.io/ios/app/daf-delayed-auditory-feedback/id606979390/reviews.md ## What is DAF Delayed Auditory Feedback? 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. ## Key features - Delayed auditory feedback simulation - Voice input via microphone - Audio output through headphones - Psychological experiment tool - Adjustable delay effects - Speech disruption testing ## Recent user reviews (10 of 10) All indexed reviews: https://appshunter.io/ios/app/daf-delayed-auditory-feedback/id606979390/reviews.md ### 5/5 — Thanks for this app *2025-12-09* I have stutters in my speech, this App force me to speak slowly. ### 3/5 — Microphone not working *2024-09-08, version 1.2.1* I’m using my WH-1000XM4 headphones and this app chooses to use the built-in microphone from my iPhone 11. The audio input should be set to the headphones, and it’s not an issue with my iPhone either since when I record a voice memo it goes through the headphones. ### 2/5 — イヤホンをさすと落ちます *2021-11-23* パーキンソン病でこちらを愛用させていただいていました。iPhone6sPlusの時は問題なく使えていたのですが、iPhone8Plusに変えたらイヤホンをさすと落ちるようになってしまいました。こちらのアプリが使えないことでとても不自由しております。早急に改善していただけないでしょうか。 ### 5/5 — 使いやすい！ *2021-03-12* とても使いやすいです！ どの機種でも出来ました！ ### 1/5 — 全く使えないアプリ *2020-08-25* すぐに落ちます。やる気がないのかな？🤔 ### 1/5 — Crash *2019-10-31* It won’t let me open the app ### 1/5 — ヘッドホン挿入してすぐ落ちる *2018-09-25* 前の方も指摘されていますが、i phone8でも落ちます。 ### 1/5 — Keeps crashing *2018-09-07, version 1.1.5* I’d like to try out your app but it keeps crashing when I try to launch it. ### 1/5 — イヤフォン挿すとすぐにこのアプリが落ちて全然使えません！ *2018-03-24* イヤフォン挿すとすぐにこのアプリが落ちるので全然使えません！即急に直してほしい！ **Developer response:** 現在はご指摘の不具合は解消していると思いますがいかがでしょうか。iPhone7とiPhone6S+の実機でテストしました。 ### 1/5 — イヤホンを挿すと落ちる *2018-01-02* 以前は発声練習などによく使用していました。シンプルで使いやすいため、満足していましたが、イヤホンを挿すとアプリが落ちるようになりました。挿さない状態なら今まで通りにアプリを開けるのですが、「イヤホンを挿してください」という案内に従ってイヤホンを挿した途端落ちます。必ずです。 どうにかしてほしいです。 **Developer response:** 現在はご指摘の不具合は解消していると思いますがいかがでしょうか。iPhone7とiPhone6S+の実機でテストしました。 ## Frequently asked questions about DAF Delayed Auditory Feedback ### What is DAF Delayed Auditory Feedback? DAF Delayed Auditory Feedback is an application that picks up your voice through the microphone and plays it back through headphones with a slight delay. This process, known as Delayed Auditory Feedback (DAF), is designed to make speaking difficult. ### How does DAF Delayed Auditory Feedback work? The app captures your voice and, after a short delay, plays it back into your headphones. This creates a feedback loop that can significantly disrupt normal speech patterns, making it challenging to articulate words. ### Who is DAF Delayed Auditory Feedback for? This app is primarily for individuals interested in cognitive psychology experiments. It allows users to explore the phenomenon of DAF and its effects on their own speech, using themselves as the subject. ### Does DAF Delayed Auditory Feedback have ads? Yes, DAF Delayed Auditory Feedback contains advertisements. As a free application, it utilizes ads to support its development and distribution. ### What devices does DAF Delayed Auditory Feedback support? DAF Delayed Auditory Feedback is supported on iPhones and iPods. It requires headphones with a microphone for proper functionality. ### What is the age rating for DAF Delayed Auditory Feedback? DAF Delayed Auditory Feedback has an age rating of 12+. The developer advises against letting minors, especially young children, experience DAF due to potential stress. ### What are the risks of using DAF Delayed Auditory Feedback? DAF can create a speech situation different from normal and may cause stress. Users are advised to understand the principles of DAF and use the app at their own risk, stopping immediately if any abnormalities are felt. ### How often is DAF Delayed Auditory Feedback updated? The latest version of DAF Delayed Auditory Feedback is 1.2.2, which was last updated on December 14, 2025. This indicates a relatively recent update. ## Version history (last 5 releases) ### 1.2.2 — 2025-12-14 Minor fixes. ### 1.2.1 — 2024-07-11 You can now experience DAF not only with wired earphones, but also with bluetooth headsets. ### 1.2.0 — 2024-06-20 (1) The app icon was changed. (2) Microphone sensitivity can now be adjusted. ### 1.1.9 — 2019-05-14 Rebuilt using newest SDK for improving stability. ### 1.1.8 — 2018-12-18 Minor fixes to improve stability. ## Apps similar to DAF Delayed Auditory Feedback | App | Rating | Price | Category | | --- | --- | --- | --- | | [Animal Sounds.!](https://appshunter.io/ios/app/animal-sounds/id580044747) | 4.5 (8,640) | Free | Entertainment | | [FANDOM News & Stories](https://appshunter.io/ios/app/fandom-news-and-stories/id1230063803) | 4.7 (24,049) | Free | Entertainment | | [TPAC Concierge](https://appshunter.io/ios/app/tpac-concierge/id1188478664) | 2.3 (24) | Free | Entertainment | | [The Speech Jammer](https://appshunter.io/ios/app/the-speech-jammer/id6443668066) | — | Free | Entertainment | | [Speech Jammer: Voice Delay App](https://appshunter.io/ios/app/speech-jammer-voice-delay-app/id6747054266) | 4.7 (55) | Free | Entertainment | | [Bracketology](https://appshunter.io/ios/app/bracketology/id6463115555) | 3.9 (160) | Free | Entertainment | ## More apps by Junichiro Seyama - [GazeGame](https://appshunter.io/ios/app/gazegame/id542257841) - [Which one do you prefer?](https://appshunter.io/ios/app/which-one-do-you-prefer/id555872494) - [Average Face PRO](https://appshunter.io/ios/app/average-face-pro/id560519978) - [Bucephalas](https://appshunter.io/ios/app/bucephalas/id627895774) - [Bucephalas Ephemeral](https://appshunter.io/ios/app/bucephalas-ephemeral/id870925809) All apps by Junichiro Seyama: https://appshunter.io/developer/537815782 ## Related topics [daf delayed auditory feedback](https://appshunter.io/ios/topics/daf-delayed-auditory-feedback) · [auditory feedback](https://appshunter.io/ios/topics/auditory-feedback) · [delayed auditory feedback](https://appshunter.io/ios/topics/delayed-auditory-feedback) --- *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 2026-08-19.*