How to Use a Spirit Box: A Practical Guide

What a spirit box is

A spirit box — also called a ghost box — is a radio receiver that sweeps continuously across the AM or FM band without settling on a station. Each frequency is held for a fraction of a second, so what comes out of the speaker is a stream of static broken by tiny fragments of whatever the receiver passed over: a syllable of a news report, half a note of music, a burst of interference.

The idea was popularised in the early 2000s by Frank Sumption, whose hand-built “Frank’s Box” inspired a wave of copies, and later by commercial units such as the P-SB7. Many modern spirit box apps do not tune real radio at all: phones have no FM tuner that an app can reach, so they play back synthesised or pre-recorded audio instead.

Why people hear words in the sweep

Investigators use a spirit box because the fragments sometimes seem to form words or answer questions. The best-understood explanation is auditory pareidolia: the brain is built to find speech in noise, and short, ambiguous fragments are exactly the material it does this best with. Once you are told what a fragment “says”, you will usually hear it that way.

That does not make a session pointless — it is a striking listening experience, and many people run them for the atmosphere alone. It does mean that the way you run and review a session matters far more than the device.

How to run a spirit box session

1. Use headphones. Static and speech fragments share the same frequency range, and small speakers lose most of the detail.
2. Pick a quiet room and keep the volume moderate. Loud static is fatiguing, and tired listeners hear more in noise.
3. Set the sweep rate. Faster sweeps give shorter, more broken fragments; slower sweeps let each one run longer. Most investigators settle somewhere in the middle.
4. Balance static against signal. A thick static bed with occasional breakthroughs is the classic sound; more signal makes fragments more frequent and clearer.
5. Record the session on a second device, such as a phone running the EVP Recorder, so you can review it later rather than relying on memory.
6. Ask questions with pauses between them, and say aloud anything that happens in the room — a car outside, someone moving — so it is on the recording.
7. Mark the time of anything you think you heard. The Ghost Box logs events and your own markers with timestamps and exports the log.

Reviewing what you heard

The most reliable review is blind: play a marked fragment to someone who was not there, without telling them what you think it says, and ask them to write down what they hear. If three people write three different things, the fragment is ambiguous, however clear it seemed in the moment.

It also helps to know what is in the source. A sweep over real radio contains real speech, so recognisable words are expected. Ghost Radio logs the actual station behind each fragment, which makes it easy to check where a phrase came from. A fully synthesised sweep, like the Spirit Box here, contains no real words at all — which makes it a useful control for how much your own ear is filling in.

Choosing settings

• Sweep rate: start in the middle. Very fast sweeps become texture; very slow ones become ordinary channel-surfing.
• Static level: high enough to mask the gaps between fragments, low enough not to tire you.
• Bandwidth: narrow bandwidth sounds like a weak, distant receiver; wide bandwidth is cleaner but less atmospheric.
• Session length: ten to fifteen minutes is plenty. Long sessions are hard to review and listening quality drops.

Spirit box, ghost box and ghost radio

The names overlap and are often used interchangeably. On this site, the Spirit Box is the synthesised sweep on its own; the Ghost Box adds live signal analysis and session logging; Ghost Com puts the same engine behind a single handheld meter; and Ghost Radio scans real internet radio stations instead of synthesising them.