Avalanche transceivers interference: phones, watches, gloves, socks…

At HAT we very often get asked about phone interference with avalanche transceivers. Indeed, as recent research shows, it’s not just phones — a surprising range of electronic devices can interfere with your beacon.

In a real rescue, avoiding this interference can mean the difference between a smooth, focused search and a chaotic, potentially fatal delay.

This article distills the most credible research and turns it into clear, practical guidance you can remember and apply instantly in the field.

The problem : Active Interference

There are many things that can interfere with transceiver reception:

• Metal objects (shovel blades, foil wrappers)
• Active forms of interference such as personal electronic devices: smartphones, smart watches, smart rings, electronic glove warmers

It’s these active forms of interference that are the focus here, because they significantly affect transceivers in SEARCH mode.

Ghost signals (officially ‘False positives’) – what they are and why they matter

Our experience and feedback from people searching is that transceivers can be “nervous” or “twitchy” — meaning they don’t guide you as steadily as, for example, GPS in a car, even in optimal rescue conditions.

This is especially true during the initial Signal Search Phase. It often shows up for users as difficulty following the transceiver’s direction arrows and distance readings because they can be erratic e.g. a directional arrow pointing back up the slope to where you have just been.

This is known often as a ‘ghost signal’ or  more technically a ‘false positive’— a false reading indicating incorrect distances or directions.

A ghost signal most often occurs when the transceiver is processing weak or non-existent signals – especially, but not always, in the Signal Search Phase. BUT this behaviour becomes much worse when electromagnetic distortion is introduced — usually from active electronic devices nearby.

The result can be misleading arrows, fluctuating distance readings, confusion, and wasted precious rescue time… while the victim(s) is suffocating under the snow.

What the research shows on SEARCH mode…

Black Diamond Equipment tested common gadgets and found that interference doesn’t make your transceiver suddenly stop — it quietly reduces its performance, without you realizing it. Here are their results (see the full report here):

Heated gloves:

• Highest setting: 90% interference
• Switched off: 0%

Smart watches and GPS watches:

• Smart watch on searching hand: 24%
• GPS watch on searching hand: 50%
• GPS watch on non-searching hand: 13%

Smart rings:

• On searching hand: 90%

Smartphones:

• Pants pocket: 15%
• Breast pocket: 13%

Other devices:

• Headlamp: 0–30%
• Electronic airbags: 2–29% (we’ll cover this in our upcoming Airbags article)
• GoPro (helmet-mounted): 4%

These numbers represent each item tested individually — if you’re carrying multiple devices, the interference could be significantly higher.

Following this simple, practical advice reduces interference, ensuring your transceiver guides you to the buried person — saving crucial time.

Quick Reference – Avoiding Interference

• SEND mode: You can keep devices on but 20 cm away from your transceiver.
• SEARCH mode: Switch devices off (fully off, not airplane mode) and keep them 50 cm away from your transceiver. In the case of a phone, the quickest thing would be to throw it to someone else who’s not searching.

Bibliography

1. Brugger H, et al. Electromagnetic Interference from Heated Gloves Impairs Avalanche Transceiver Function. Wilderness & Environmental Medicine, 2022
2. UIAA. Electromagnetic Interference in Avalanche Transceivers. UIAA Safety Commission, 2023
3. DAV Safety Research. Effects of Electronic Avalanche Airbag Systems on Avalanche Transceivers, 2023
4. Genswein M, et al. Recommendations on How to Avoid Interference Issues in Companion and Organised Avalanche Rescue. ISSW 2013
5. Black Diamond Equipment. Electromagnetic Interference Testing with Avalanche Transceivers, 2023.
6. Avalanche Canada and Utah Avalanche Center collaborative guidance, 2023

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Check out our Backcountry Smarter events this coming Autumn/Winter 2025/26 featuring a UK Tour of talks and transceiver training, and new on-snow courses in Val d’Isère where you get to put everything into practise, learn about off-piste equipment and improve your ski technique.

AND For safer, more fun off-piste and ski touring see our 12 minute pocket guide on video:

By Henry’s Avalanche Talk in partnership with ORTOVOX

Safety is Freedom