The Static Shuffle: Spirit Boxes and Portals

Spirit boxes started as a DIY twist on EVP work. In the early 2000s, hobbyists and inventors began modifying AM/FM radios to sweep through frequencies at rapid speeds. The idea was that spirits could manipulate the white noise to form words or phrases in real time.   

Portal devices came later. These are usually spirit boxes hooked into guitar pedals, reverb processors, noise gates, and amplifiers, all with the goal of smoothing out the audio and making “spirit communication” clearer. They look sleek, but the question remains: are they really filtering out noise or just filtering in human bias?

🔬 The Science

At their core, spirit boxes rapidly scan radio frequencies. As they move through AM or FM bands, they momentarily catch snatches of actual broadcasts: bits of DJ chatter, commercials, and talk shows.

Paranormal proponents argue that spirits can use these random words to answer questions. From a scientific standpoint, several phenomena may explain what’s going on:

• Apophenia and Audio Pareidolia: Our brains are wired to find patterns in random input. That’s why people hear their name in white noise or recognize a phrase like "get out" in a burst of static.
• Radio Bleed: Unless heavily shielded, these devices catch actual terrestrial radio. In urban or semi-rural areas, that means background noise isn’t random—it’s just low-fidelity news radio.
• Lack of Controlled Variables: With constantly changing input, there’s no baseline. Every session is a one-off.

🧪 The Lab: Try It at Home

DIY Experiment: “The Faraday Filter Test”

What you need:

• A spirit box or hacked radio scanner
• A Faraday bag or shielded box (you can make one with copper mesh or aluminum foil-lined container)
• Headphones
• Notepad

Steps:

1. Conduct a spirit box session in a room with your device out in the open.
2. Ask a series of questions, recording any perceived responses.
3. Next, place the device in the Faraday container to block radio signals. Ask the same or similar questions.
4. Compare the two recordings. Are there fewer "responses" in the shielded version? Are they less coherent?

Purpose: If radio signals are blocked and you get silence, that’s evidence the device was picking up existing transmissions, not spirit communication.

⛔ Debunking the backwards sweep 

The claim that sweeping a spirit box backward avoids radio interference is not supported by evidence. 

Here's why: 

• Radio waves are not directional in this sense: Radio interference stems from the presence of broadcast signals in the environment. Sweeping forwards or backward simply alters the order in which the spirit box encounters these signals, it doesn't diminish their presence or impact.
• Spirit boxes function by design to pick up radio signals: Their core function relies on receiving radio waves and converting them to sound. To intentionally block or avoid all radio waves would defeat the purpose of the device.
• The appearance of avoiding interference is likely subjective interpretation: If sweeping backward seems to produce clearer results, it's more likely due to a combination of factors:
  • Auditory Pareidolia: The brain's tendency to perceive patterns or meaning in random sounds.
  • Confirmation Bias: Users may be more likely to interpret ambiguous sounds as meaningful messages when they expect to avoid interference.
  • Random Chance: The chaotic nature of radio waves means that some sweeps (forward or backward) may coincidentally yield less fragmented audio than others. 

Ways to minimize radio interference (if you choose to use a spirit box)

While it's impossible to completely eliminate radio wave interference, some techniques can potentially minimize its effect:

• Move away from strong broadcast signals: Operating in areas with weaker radio station presence can reduce the amount of broadcast audio heard.
• Experiment with different sweeping speeds: Adjusting the speed at which the device sweeps through frequencies may make it easier to discern potential voices from random noise.
• Remove the antenna: This may reduce the overall sensitivity of the device and potentially pick up fewer distant or weaker signals, according to one Facebook group post.
• Utilize a Faraday pouch or fabric: These can help block out a portion of the incoming radio signals, allowing for more controlled experimentation. 

🎛️ PIMN’s Take on Spirit Boxes and Portals

It's important to remember that the scientific community remains skeptical about the efficacy of spirit boxes for communicating with spirits. The perceived voices or messages are often attributed to auditory pareidolia and confirmation bias. 

If using a spirit box, a critical approach, combined with recording and reviewing sessions objectively, is recommended.  As such, we don’t use these as primary tools in scientific investigations.  However, we sometimes include them as part of public experiments or field sessions for engagement and curiosity.

To reduce radio contamination, we run tests inside Faraday bags. If a session yields coherent responses while fully shielded and double-blind, now that might warrant further exploration.

⚠️ Practical Use & Pitfalls

• Watch for wishful hearing. It’s easy to "hear" responses that fit your question after the fact.
• Question the source. Many “responses” are local DJs or weather reports that sync up with your expectations.
• Don’t conflate clarity with validity. Reverb and audio gates can make gibberish sound profound.

🧾 References and Further Reading

• Radford, B. (2010). “Scientific Paranormal Investigation: How to Solve Unexplained Mysteries.”
• Spirit Boxes, Ghost Boxes & Radio Voice Phenomenon | Higgypop Paranormal 
• Hellkson, L. (Lauren Haunts). Interview on best practices for motion detection in haunted locations. PIMN Podcast Episode 2 Parts 1 and 2
• National Radio Quiet Zone. “Why Radio Signals Travel Differently in Different Conditions.” https://www.nrao.edu