Don't take our word for it
A spirit box app that sweeps live radio goes silent in airplane mode, names its stations, and lets you trace any fragment to a broadcast. One that plays a word bank keeps talking with the radio off. Here is how to check, and what SpiritBox shows.
Most of the category is built on sound banks: recorded phonemes, word lists, text-to-speech, triggered by a random number or by the phone's sensors dressed up as an EMF meter. One developer admitted on record that his app is "an algorithmic random word generator". The community's own test for this is simple, and it works on any app, including ours.
Three tests, thirty seconds each
Test 1 — airplane mode
Start a session, then switch on airplane mode. If the audio comes from live radio, the streams die and the app goes silent within seconds. SpiritBox does. An app whose "voices" continue has them stored on the phone.
Test 2 — read the log
Record a session and open its source log. SpiritBox lists every station that became audible, with its country, codec and bitrate, and the second it happened. If an app cannot tell you where a sound came from, it is because it came from a file.
Test 3 — look the station up
Every station name in the log is a real entry in the public radio-browser.info directory. Search it there, open its stream in any player, and you are listening to the same broadcast the app swept.
A real session
Recorded on the app on 7 August 2026, FM band, 200 ms dwell, ANC off. This is the review screen's log, transcribed: a Chinese regional broadcaster, a Hungarian dance station, Virgin Radio Türkiye, a Romanian station and a NOAA weather transmitter, in 20 seconds. Random stations from the global directory, exactly as the engine picks them.
SPIRITBOX SESSION 2026-08-07T18-41-16 dwell 200 ms · anc 0.00 00:01.6 BLEED 阳信广播电视台 · CN 00:01.8 TUNE 阳信广播电视台 · CN · MP3 0 00:02.0 BLEED 阳信广播电视台 · CN 00:02.2 AIR 00:07.2 BLEED Dance Wave! · HU 00:07.4 TUNE Dance Wave! · HU · MP3 128 00:07.6 BLEED Dance Wave! · HU 00:07.8 AIR 00:08.0 MARK 1 ← (air) 00:11.3 BLEED Virgin Radio Türkiye · TR 00:11.5 TUNE Virgin Radio Türkiye · TR · MP3 64 00:11.7 BLEED Virgin Radio Türkiye · TR 00:11.9 AIR 00:17.3 BLEED Radio Brașov · RO 00:17.5 TUNE Radio Brașov · RO · MP3 192 00:17.7 BLEED Radio Brașov · RO 00:17.9 AIR 00:19.3 BLEED WWG57 162.450 NOAA Weather Radio · US
Read it like a tuner: a station is approached (BLEED), hit for one step (TUNE, 200 ms), left (BLEED), then air. The MARK at 00:08.0 was pressed on empty dial, and the log says so.
What we claim, and how you can check it
| Claim | How to check |
|---|---|
| Every sound is live radio or synthetic noise | Airplane-mode test; the source log; look any logged station up in the directory |
| No word banks, phonemes or text-to-speech | Airplane-mode test: with no connection there is nothing left to play. Unpack the APK: there are no audio files in it |
| Nobody chooses what you hear | Station positions are random per session; the cursor steps at a fixed rate; broadcasts are live |
| Every fragment is traceable | The log names station, country, codec, bitrate and second for every TUNE and BLEED |
| The stations are real | Each one is a public entry in radio-browser.info; the app reports plays there like any client |
What the app does not do, said plainly
- It does not detect anything. There is no EMF meter, no "energy" reading, no sensor used as an oracle.
- It does not claim that voices come from anywhere other than the radio. If you hear a word, the log tells you which broadcast it came from.
- It does not work offline. Live radio needs a connection; that is the whole point.
- It does not use your phone's FM chip, because almost no phone exposes one. It uses internet streams.
Questions
How do I know the log is not made up?
Because every line in it points outside the app. Each station is a public entry in radio-browser.info that you can open in any player, and the timestamps line up with the WAV second by second. A log that could be faked would name stations that do not exist, or broadcasts that were not on air at that moment; this one can be checked line by line.
Why do fragments sound like words?
Because a 50–350 ms grain is syllable-sized and your speech perception joins grains into words — auditory pareidolia. Hardware spirit boxes rely on the same effect. The app reproduces the instrument; it does not add anything to make the effect stronger.
Could a station be playing a word bank?
A station can broadcast anything, including speech synthesis. That is a property of the broadcast, not of the app, and the log tells you which station it was so you can check.