Why spirit box apps with word banks aren't spirit boxes

Inside, the recipe is short. A set of audio files: recorded phonemes, partial words, or a dictionary of whole words, sometimes with echo and reverb mastered in. A trigger: a random number generator, or the phone's magnetometer and accelerometer read and presented as an "EMF" or "energy" level. And a player that fires a file when the trigger crosses a threshold. Some use the phone's text-to-speech engine instead of recordings, so the vocabulary can be any list of words.

None of that is radio. The sensors are real sensors, but a magnetometer measures the phone's orientation in the Earth's field and nearby metal; presenting it as a detector of anything else is a label, not a measurement.

Turn on airplane mode. An app that sweeps live radio loses its streams and goes silent within seconds. An app that keeps producing voices has them on the phone. The paranormal community has used this test for years, and it is how the first big case was settled: the developer of Spirit Story Box, asked why his app kept "detecting" with every radio off, acknowledged that it is "an algorithmic random word generator".

Two more signs that need no technical knowledge: an app that charges for "more words" is selling a longer list, and an app with a radar screen and blips is decorating a random number.

This page names only what the developers themselves or published investigations have stated.

• Spirit Story Box — its developer described it as an algorithmic random word generator; it continues to produce words in airplane mode.
• GhostTube — its developer states that "no app is scientifically proven", and the app family uses a word dictionary triggered by sensors, a machine-learning silhouette detector (the SLS variant) and generated imagery. Credit to them for the disclaimer: transparency is rarer than it should be.
• Spirit Talker — a word base with the phone's sensors as entropy and the system text-to-speech engine as the voice, which is why its "voices" sound like the phone's narrator.
• Higgypop's audit of more than fifty ghost-hunting apps found that the random-word apps do not even request location permission — ending the myth that they consult a "graveyard GPS".

Other apps in the category describe themselves as "ITC tools" with "sound banks". Whether a given one plays recordings is something you can establish yourself with the test above; we have not tested them all and do not claim to have.

Hardware spirit boxes — the P-SB7, the SB11, Frank's Box — are radios that never stop on a station. The software equivalent keeps several live internet radio streams open and makes one audible at a time at a fixed dwell, with noise between hops. The community's own criteria for a legitimate app follow from that: a raw, unpredictable audio source (live radio or a live microphone); no word banks or text-to-speech; adjustable sweep speed and direction; raw WAV recording with review tools; and developers who state their limitations plainly. Several apps meet them, SpiritBox among them; the proof page shows how to check.

A word bank cannot say anything its author did not record. Whatever one thinks of the premise of a spirit box session, a sweep of live radio at least produces material nobody chose, in real time, from sources you can name. That is the minimum for the exercise to mean anything, and it is the line between an instrument and a toy.