A clip goes round of someone asking a question into a crackling app, and a voice seems to answer with a word that fits. The obvious question is whether the phone picked something up, or whether it is a trick.
So, do spirit box apps work? On iPhone, a spirit box app cannot be picking up radio from the air, and the reason is the hardware and iOS rather than opinion. Once you know where the sound comes from, the useful questions are whether an app is honest about it, and whether it is fun.
What a spirit box was built to do
A hardware spirit box, also called a ghost box, is a modified AM/FM radio. Instead of settling on a station, it keeps sweeping through the frequencies, so what comes out is static broken by short bursts of whatever is broadcasting: half a syllable from a presenter, a beat of music, a slice of an advert.
Those bursts are real radio. They are also very short, and a fragment too brief to recognise as a DJ is easy to hear as a single word. A hardware box, in other words, needs a radio receiver.
Why an iPhone app cannot sweep the radio
An iPhone has several radios — cellular, Wi-Fi, Bluetooth, GPS — but each is locked to its own job, and none is a broadcast receiver an app can tune. iOS gives apps no AM/FM tuner to work with. No setting, permission or developer tool turns the phone into a scanner.
Apple has been explicit about FM. In September 2017, when it was asked to switch on FM radio in iPhones, Apple said the iPhone 7 and iPhone 8 have no FM radio chips and no antennas designed for FM signals.
So no iPhone spirit box app is sweeping stations over the air. That is not a judgement about any app; it is what the hardware and iOS allow.
Follow along in Ghost Hunt: Spirit Box & EMF
Free on the App Store for iPhone and iPad.
App Store
Where the sound in a spirit box app comes from
If it is not coming from the air, the app is supplying it, usually in one of two general ways or a mix of both.
Generated sound. The app synthesises noise and shapes it to sound like a radio between stations: hiss, crackle, the warble of a sweep, moments of dead air. Words are picked at random and filtered to sound like a tinny speaker.
A built-in sound bank. The app carries recordings of static and spoken words, and plays them in shuffled order.
Either way, the app decides what you hear. Random, here, means code choosing the next sound: unpredictable to you, but not picked up from the air. That is not a flaw. A well-made sweep can sound convincing, which is what makes it work as entertainment. The problem starts only when an app lets you believe the sound is something else.
Why the words still feel like answers
Auditory pareidolia is the brain's habit of hearing meaningful speech in noise, the way people see faces in clouds. Asking a question primes it: you are already listening for a name or a yes, so an ambiguous syllable becomes one. In a group, once someone says what they heard, others tend to hear the same word on the replay. No controlled study has shown that a spirit box, hardware or app, communicates with anyone. What a spirit box is covers the history and the psychology.
Ghost Hunt, the spirit box and EMF app this site makes, uses no microphone, so it cannot hear your question at all. When a generated word seems to fit, that is coincidence plus pareidolia, and nothing more.
How to tell an app that is honest with you
Because no iPhone spirit box app can tune the radio, honesty about where its sound comes from is what separates them. Check the App Store listing and the app itself for these.
- It says what the sound is. A plain line saying the static and words are made by the app, and that nothing is received.
- It labels its output. Ghost Hunt marks every word on screen as "Generated word", so you are never left to guess.
- It discloses any link to sensors. If words are tied to a sensor reading, the app should say so.
- It does not ask for what it cannot use. A generated spirit box has no use for a microphone, a camera or an account. Ghost Hunt asks for none of them.
- It keeps real and generated apart. Ghost Hunt's investigation log records real magnetic spikes and generated words separately.
A spike is not a reply
Ghost Hunt has an optional link that, when switched on, makes words appear more often as the magnetic reading rises, and the app tells you it is doing this. The reading is real, from the iPhone's magnetometer, but it rises for ordinary reasons: a magnet, a MagSafe case, electronics, or iron and steel nearby. A word during a spike is the app doing what it said it would: part of the game, not a response.
Where spirit box apps do work: as a shared game
A spirit box app is at its best as a shared, slightly theatrical game. Dim the lights, put the phone in the middle of the table, and take turns asking questions while everyone argues about what they heard. The fun is in the interpretation, and it works just as well when everyone knows the words are generated.
Ghost Hunt lets you set the sweep speed, its direction, the noise level and how often words appear. A slow sweep with sparse words builds tension; a fast, noisy one turns to chaos quickly. The ghost hunt party game guide has rounds that suit a group.
The EMF meter is the other half. It reads the iPhone's magnetometer live and shows the change in microtesla from your room's baseline, a real if simple way to see magnets, iron and steel close to the phone. Whether an iPhone can measure EMF explains what that sensor does and does not pick up, and the ghost hunting equipment guide covers the rest of the kit.
Quick answers
Can a spirit box app pick up real radio stations on iPhone?
No. iOS gives apps no AM/FM tuner, and Apple has said the iPhone 7 and iPhone 8 have no FM radio chips. So an app cannot receive stations over the air: whatever it plays comes from the app itself or from the internet, not from a tuner. Ghost Hunt's static, sweep and words are all generated by the app.
Why did the app say a word that matched my question?
Chance, combined with pareidolia. Your question primed you to hear a particular word, and an ambiguous sound filled the gap. Ghost Hunt does not use the microphone, so it could not have heard you.
Is a hardware spirit box more real than an app?
It picks up real radio, so its fragments are genuine broadcasts: real people on real stations, not messages.
Does a spirit box app need my microphone?
Not to make its sound. Ghost Hunt uses no microphone, no camera and no account. If an app asks for it, check what it says the microphone is for.
Where to get it
Ghost Hunt: Spirit Box & EMF pairs a generated spirit box, with every word labelled, with an EMF meter that reads the real magnetometer. It is free with ads and made for entertainment: the Spirit Box does not contact spirits.
Ask your questions, enjoy the static, and keep the light switch within reach.