There seem to be metal detectors everywhere these days, and my headphones are like my shoes, I wear them everywhere. I’ve accidentally taken them through metal detectors a few times; sometimes they go off, sometimes they don’t.
Also, I’ve heard a high-pitched sound once or twice while walking through a metal detector. So, I was wondering why my headphones set off metal detectors and if it could damage them?
Headphones will make it through metal detectors unharmed, but depending on the security settings, as with any metal devices, headphones and earbuds may set off the alarm if you don’t take them off before walking through the metal detector.
There are so many different types of metal detectors and reasons why people check for metal objects; to be on the safe side of the law (or your local librarian), let’s look at all the different scenarios.
Will Library and Store Detectors Damage Headphones?
Not all metal detectors were created equal. The metal detectors you see at the library and department stores aren’t aimed at detecting just any old metal; they’re geared towards detecting any metal leaving the premises that shouldn’t be leaving the premises.
Your library books and almost every single product you buy at the department store, all have a double-layered magnetic strip on them. Sometimes they’re hidden but trust me; they’re there.
One side of the strip is permanently magnetized, while the other side can change polarization.
When you buy a product or check out a library book, the changeable magnetic strip is then polarized (by scanning the strip) one way, in order to desensitize it so it can go through the metal detector.
But, why the high-pitched noise when I walk through library and store detectors? Are they damaging my headphones?
The radio waves transmitted by metal detectors temporarily disrupt electrical currents in your headphones. This is picked up by the voice coil in your headphone drivers, resulting in the high-pitched noise. However, the radio waves aren’t strong enough to do any permanent damage to your headphones or earbuds.
While it’s irritating, it’s good to know that no harm will come of it. If you are worried though, just turn them off as you walk through. If that hasn’t satisfied your curiosity, let’s take a deeper look at the technical side.
How Does Electrical Interference Disrupt My Headphones?
Your headphones produce sound by interpreting electrical currents. Every time a beat comes through your cord to the driver as an electrical signal, it moves the voice coil via a magnetic push and pull. This moves the diaphragm, which makes the sound.
While how headphones work is fascinating (tech has come far), what we really want to know is how the signal transmitted from the detector messes it all up.
The electromagnetic signals transmitted by the metal detectors at the library or store are daily low frequency.
This is picked up by the metal parts in your headphones (there are many) and amplified. This eventually reaches the voice coil, which gives an extra wobble, moving the diaphragm and causing the high-pitched sound.
Interestingly, some high-quality headphones actually have filters built in to negate the interference. If you have to go through these detectors multiple times a day, you might want to make sure your next pair has that feature.
Will Airport X-Ray Machines Damage Headphones?
So, you’re flying somewhere, and you know the drill – it all comes off when you get to the metal detector. Once it’s all neatly stacked in the tray, it goes through to the X-ray machine. Safe, right? Well is it? How does an X-ray machine actually affect your headphones?
X-rays are a form of electromagnetic radiation. They are not magnetically charged, and therefore cannot damage your headphones. Your headphones can, however, be affected by the strong magnetic pulse sent out via the Airport metal detector or handheld scanner. Always take off your electronics.
I always get irritated when I have to take (almost) everything off at the metal detectors, but I think from now on I’ll just be thankful it’s getting to the other side safely.
How Can Airport Metal Detectors Affect My Headphones?
While most of the time you will be asked to remove your headphones, and they’ll safely pass through the X-ray machine, what happens the day they don’t stop you, and you end up going through the metal detector?
First off, you’re going to set it off, most likely. I hope by that time, you’ll realize your headphones are on and then take them off before you walk through it again (if they’ll even allow that).
So, what’s probably happened to your headphones?
If they were off, probably not much. If they were on, the strong magnetic pulse could have pulled at your voice call, but the chances of it damaging your headphones are slim to none.
High-end electronics have safety features in place to ensure that random magnetic pulses don’t affect your driver.
For anything else, just give it a listen to see if it was affected at all. If it’s still under warranty and there is any persistent issue, you could have it replaced.
■ Final Thoughts
Your headphones can set off the metal detectors. If this happens at an airport, there is also the chance that the magnetic pulse of the detector could affect your headphones. This shouldn’t cause permanent damage, but it could result in a loud screech that can harm your hearing.
Always either turn your headphones off while going through a metal detector or opt for a higher-quality brand that has special features in place to nullify any interference.
As a rule:
- Your headphones should be able to handle going through any basic screening or metal detectors you might find at school, at work, or at the department store.
- You need to take a bit more caution when using your headphones on flights, as the strong magnetic metal detectors can have an effect on your headphones.
- While permanent damage due to metal detectors is highly unlikely, if you are still under warranty, you will be covered for it.