Antiphon · Privacy policy · the same text as in the app · Terms of use

Antiphon — what happens to your recording

Last changed October 18, 2026.

Antiphon turns a recording of someone worth imitating into a lesson: sentence clips, word clips, slow copies, a rhythm copy that makes the beat obvious, a dictation of the real voice. Cutting it needs a server, because it means transcribing speech with word-level timings and running ffmpeg a few hundred times — minutes of work and several gigabytes of memory, which no phone will do.

So the recording is sent. It is cut. It is not kept. The lesson that comes out is yours and lives on your phone. This page says exactly that, in enough detail that you could check it against the code.

What leaves your phone

The recording you chose, and the fact that you chose it. If you add a link instead, the address you typed. If you give the words with it — a transcript or subtitles you picked beside the recording, or the words another of our apps sends along when it hands you something to practise — such as the sentence of a click from Mimesis or Lectio, a text with the phone's own synthetic voice reading it from Phonema, or chunks of a text from Semantica — those words go with it, so the service only has to line them up; they are deleted with the recording. Nothing else: no account, no name, no email address, no device identifier, no advertising id, no location, no analytics, no crash reporting. The service has no idea of a user at all, because there are no accounts.

It is not even told what you called the lesson. The app names it here, on your phone.

Later, while you practise, three more things may go — one at a time, each for one answer:

• a clip of the lesson (about two seconds of the speaker) when you ask for its rhythm copy, its dictation, or what an American mouth really does to that line;
• your own recording, when you say a line and ask how close you got — together with the clip it is being compared against, because the service does not have the lesson and has to be given both;
• a recording of you saying anything, in free practice;
• a few sentence clips and a plan, when you make the shadowing track as an MP3 — the service joins them into the file, sends it back and keeps nothing.

What the server does with it

It writes your recording into a working area made for that one build: a folder of its own, under a name that means nothing outside it. Then it transcribes the speech with timings, looks the words up in a pronunciation dictionary, and cuts the clips. When the app collects the lesson — one stream, the clips and the text together — the working area is destroyed as the last byte goes out. Collecting is what deletes it; there is no separate tidying step to forget.

If your phone never comes back for it — the battery died, the network went — the build is swept away anyway, within sixty minutes at the outside. That number is a failsafe against a crash and not an offer to keep anything: it is minutes because your recording has no business sitting on a machine for longer, and there is deliberately no setting that can turn it into days. Whatever a killed process left behind is purged when the service next starts.

A build that fails has its files removed immediately. A recording that could not be cut is of no use to anybody, so it does not outlive the error.

Every other request is one request: the clip or the recording you sent is written into a folder for the length of that call, read, and the folder is removed before the answer leaves. Nothing waits for a second request.

So there is no library on the server, no cache, no queue you sit in, no backup and no retention period — nothing to retain, nothing to ask us to delete, and no lesson of yours to come back to tomorrow, which is why the lessons are on your phone.

This is tested, not promised. The service's test suite walks the whole working area after a lesson has been collected, after an attempt has been scored, after free practice, and after an upload that was refused, and fails if a single file is left anywhere the service can write. Two more tests prove the failsafes: a build nobody collected is gone after the hour, and anything a crashed process left behind is purged at startup.

The logs record sizes, counts and how long things took — never content. A line may say that twelve chunks were cut, or that a package of 41 MB went out. No line carries a word that was said; where a failure message would have quoted a clip's file name — and a clip is named after the words in it — the name is left out and only the kind of failure is written down.

Where the listening happens

Inside the service, on the machine it runs on. The speech recogniser (Whisper, with word timings) and the recogniser that reads what was actually said (wav2vec2) are files in the service's own container. Your audio does not reach Google, OpenAI, Amazon or anyone else, because nothing in this path makes an outside call.

The library the service is built on *can* use a Google model to help decide where one sentence ends and the next begins, for someone running it as a desktop script with their own key. The service never does: it passes no such client, and the local segmenter does that job. Antiphon also calls no other NeuroPhonetics service — not Phonema, not Lectio — because it is sold on its own.

One exception, and it is yours to make: if you add a lesson by link, the service downloads that address, which means the site you linked to sees a request (and the service's own network address, not yours). Adding a file from your phone involves nobody.

What is kept, and where

On the server: nothing.

On your phone:

• the lessons you have built — the clips, the text, the pronunciation, the timings — in Antiphon's own private storage;
• rhythm and dictation copies you have played, kept beside their lesson so the second press needs no network;
• your practice: your scores, which sounds keep letting you down, how your dictations went, what you typed while marking one;
• the words you saved, with the line you heard them in;
• your settings.

If you choose Store lessons on the SD card (Settings → Storage), the lessons go to Antiphon's own folder on the card instead; everything else stays on the phone. Your attempts are not kept on the phone either: a recording lives in the app's temporary folder until you record again or leave the screen, unless you press Save mine, which puts it in Documents/Neurophonetics/Antiphon as a small M4A file you can see and delete.

Playlists from Mimesis, Lectio and Phonema (0.7.0, "From the family"). If you choose a folder for it — once, in Android's own folder picker, normally Documents/Neurophonetics — Antiphon may read that folder and nothing else: it lists the VLC playlists the other apps exported there and, when you import one, copies its clips and subtitles into its own lessons on this phone. It never writes into that folder, never sends what is in it anywhere, and Android lets you take the choice back at any time (Settings → Apps → Antiphon, or "Change" on the same screen). Align words sends each imported clip with its sentence to the service, which works out when each word is said and deletes both in that same request.

If the app crashes or hits an error, it keeps a short technical record of it — what failed and where in the code, the app and Android versions, and the time, with no text, words, books, recordings or file names of yours — on your device only, in storage that is not backed up; it is never sent automatically, and leaves your device only if you choose to send it in a problem report you can read first. You can see it, and clear it, in Settings → Report a problem (Problem log and Diagnostics). Both logs keep 30 days of entries unless you choose 7 or 90 under "Keep logs for"; older entries are deleted.

Logs from your other devices. A problem report written on one device can include the problem and crash logs of your other paired Antiphon devices — a tablet, for example — when you choose them on the report page. Each paired device keeps its own log ready for the devices it is paired with and switched on in "Devices"; another device's log travels only over your own Wi-Fi, between paired devices, into the email you read before you send it. Your "Keep logs for" choice travels the same way. Nothing goes to us or to any server unless you send that email.

Uninstalling the app removes all of it. Android's own cloud backup does not copy it.

Your own mp3 is never copied anywhere by us. It is your file, already on your phone or in your podcast app; the app reads it to send it for cutting and does not keep a second copy, and neither does the service.

Copies you choose to make

Your practice record — scores, weak sounds, the lessons you have made, never audio — can be copied, and only if you switch it on:

• Google Drive, into a Neurophonetics/Antiphon folder in your Drive, with the drive.file permission, which reaches only files Antiphon itself created;
• a file on this phone, Documents/Neurophonetics/Antiphon, visible in the Files app, yours to copy to a computer;
• Wi-Fi sync, handed straight to another of your own devices on the same network, uploaded nowhere and passing through no server of ours.

We never see any of it. Nothing is synchronised unless you turn it on.

The one exception, for when it exists

If a paid version is ever sold, the record a payment requires will be stored — that is the only data that will ever rest on a server, and this page will say what it is before it does. There is no payment today, no account, and nothing of the kind is collected.

Google Play

If you get Antiphon from Google Play, Google handles the download and any payment under their own privacy policy. We see only the order information Google gives developers, never your card.

Update check (website and test versions only). When you press "Check now", or once a week if you switch that on, the app reads one public file listing the newest version from our download page. It sends nothing about you or your device — no account, no identifier, no usage, not even the app's own version; the comparison is made on your phone. "Download" opens the file in your browser, and Android asks you before anything is installed. The version from Google Play has no update check; Google Play updates it.

Help us, only when you tap it. "Rate us" opens Antiphon's page in Google Play, and only when Google Play installed this copy; to know that, Antiphon asks Android which store installed it, and the answer stays on your phone. "Tell a friend" opens Android's share sheet with one line and the address of Antiphon's page; you choose the app and the friend. "Suggestions" opens your own email app, addressed to . None of them sends us anything unless you send that email yourself.

Permissions

• Microphone — only while you are recording an attempt or practising freely. Antiphon never records in the background, and nothing is recorded until you press the button.
• Internet — to reach the Antiphon service (and, in a test version, the update page when it checks).
• Notifications (Android 13 and later) — asked when you first send a recording, for one thing only: to say "Lesson ready" when it has been cut. The notice is made on your phone; no server sends it.

Antiphon does not ask for the camera, your contacts, your location or your photos.

Security

Requests to the service travel over an encrypted connection when the service is reached over the internet. On a home network you may point the app at a service on your own machine, in which case nothing leaves your network at all.

Children

A supervised phone or tablet is a real case in this family, and Antiphon is built for it: a child's recording is treated exactly like anyone else's — cut, handed back, and gone from the server. There is no account, so there is nothing about a child to hold, and nothing of theirs is collected. Antiphon is not aimed at children under 13.

What this program never does

It does not identify you by your voice, and it could not: what it keeps is on your phone. It does not send your recordings to another company. It does not use them to train anything. It has no advertising, no analytics and no tracking of any kind.

Asking

Write to . There is no recording of yours for us to show you or delete, because we do not have one — and that is the shape of the program rather than an excuse. What you have is on your phone, and you can delete any lesson from the app at any time.

Who this is

Antiphon is made by NeuroPhonetics LLC, a limited liability company registered in the State of Minnesota, United States. NeuroPhonetics LLC is the company behind every program in this family and the seller on Google Play.

NeuroPhonetics LLC · 202 N Cedar Ave Ste 1, Owatonna, MN 55060-2306, USA

· · https://NeuroPhonetics.com