I guess I'm old now because this style of headphone was present on every model of passenger aircraft in the sky when I was a young adult.
It worked perfectly! Until a stewardess caught me and made me stop.
Pretty surprising to hear there's air/sound tubes rigged on to every seat on a plane.
Seems like the sound tubes ended in the 70's: https://apex.aero/articles/sound-tube-surprising-history-air...
Either because they didn’t want you to take their headphones from the plane, or so they could charge for use because you couldn’t just plug in your Walkman headphones.
Or both.
Either on the headphones themselves or in the little overwrap bag there was a note to leave them on the aircraft when you deplane, because they (obviously) wouldn’t work elsewhere.
I was still encountering them in the early '90s, although by that time they had become uncommon.
I'm 40-ish, and I remember them as a child, so they were definitely still kicking around in the mid to late 80s, most likely on KLM and Pan Am, that were the airlines of my childhood.
https://avidproducts.com/2023/12/08/celebrating-70-years-of-...
apparently the speaker was in the armrest.
Not sure if that was the backup plane or they were just desperately holding out to upgrade the fleet.
Having said that anyone that flew just over 30 years ago would have likely used pneumatic headphones and watched on a shared pulled down theatre screen. It was the norm not that long ago.
Edit:
From this URL: https://avidproducts.com/2023/12/08/celebrating-70-years-of-...
This type of headphones are called pneumatic headphones.
Cost: one speaker and tubes was probably cheaper than 200.
Weight: old headphones were chunky, see above.
Comfort: not wearing giant chunky headphones you weren't accustomed to might have been preferable
Breakability: pneumatic headphones were harder to break, cheaper to replace
Stealability: passengers would have no reason to steal the headphones, and if they did it was cheap to replace.
All of these go away as proper headphones get increasingly small and cheap.
Even Andrew Huberman, one of the most popular health science podcasters, has dabbled into anti-EMF quackery. On one podcast he claimed that his Bluetooth headphones produced notable "heat effects", implying that the electromagnetic energy was enough to produce palpable heat in his body.
It's obviously placebo effect to the extreme (physically impossible given the amount of RF energy) but nevertheless he made the claim. Millions of people listen to that podcast.
Of course, people are catching on that Andrew Huberman isn't really a good source of scientific information (nor really a good person, given recent revelations) but the damage is done.
a) he's obviously done a LOT of steroids or something, which aren't really great for you
b) At least half of what he says appears to be made up woo-woo nonsense
And iPhone also had this in their Product Information Guide:
"When using iPhone near your body for voice calls or for wireless data transmission over a cellular network, keep iPhone at least 15 mm (5/8 inch) away from the body, and only use carrying cases , belt clips, or holders that do not have metal parts and that maintain at least 15 mm (5/8″) separation between iPhone and the body."
1. https://www.sciencedirect.com/science/article/abs/pii/S02697...
It it was at the speed of light we might have a problem.
In contrast, consider the glut of products involving magic nonsense about hematite beads or whatever.
[0] https://www.mriequip.com/store/pc/MRI-Non-Magnetic-Magnalarm...
https://tomlingham.com/articles/an-unfortunate-hierarchy-of-...
I find the exact opposite problem, I go with old faithful over new.
It's for this reason that when I put my clothes away I simply take the stack of clothes in my dresser out, put all the fresh stuff on the bottom, then put the clothes that were in the drawer stuff on top.
I always grab the top sweater, t-shirt socks etc and I don't think about it at all.
Your linked article confirms the semi-humorous statement just a day later.
There was a YouTuber (WhiteBoy7thSt if anyone is familiar) I watched over ten years ago now that came from very humble beginnings, and when he started to make real money, his first splurge (and one he stuck with) was new socks. When I say new socks, I mean new socks most days, maybe even a new pair for every day of the year. These were normal white socks, not any nice wool socks, so it was still fairly cheap, but when he grew up, they always had beaten, old socks.
it seems 99% of gift clothing has some sort of special care requirements.
I’ve seen most these things play out. And as you say, it’s exactly what the call bell is for.
Even non-ferromagnetic materials react to the high field strength, and to show that, they let me hold a ring of aluminum just outside the bore. You can feel it "snap" to either parallel or perpendicular to the table when you try to turn it. It was a surreal experience.
I looked it up afterwards and tungsten apparently as little to no magnetic effects, but depending on the amount of carbon used in it, it can.
Oversimplification: Moving a conductor in a magnetic field or vice versa indices current in the conductor , resistance in the conductor results in heat.
The main field in an MRI is static but there are a lot of other fields moving around…
Similar happens on your body also (eddy currents) and deeper tissue gets energy which has to be controlled for - it can cause stimulation in peripheral nerves and heating .
Whether or not it’s a conductor is probably more of a concern. The loop likely wouldn’t be large enough to cause any drama though.
https://www.sciencedirect.com/science/article/pii/S193004331...
https://www.washingtonpost.com/wellness/2023/07/26/mri-yoga-...
Best practice for at least a decade is to always remove all rings and all jewelry and failure to detect rings or other jewelry is generally seen to indicate a problem in screening. That is... if a radiologist sees evidence of a ring on the images there better be an explanation. The reality is that particularly older people have not removed their rings in decades and their joint disease may have expanded so much that it simply cannot be removed and the risk/benefit doesn't justify damaging the ring nor denying them the benefits of a scan. But if the patient can't take the ring off, the magnet wont either.
Just for reference, people get head scans with braces pretty regularly and it's not considered a safety issue. Braces and rings can affect image quality though so that's usually the concern. So if the ring is near the body part being imaged you'd probably be asked to remove it because they'll easily cause undesired issues (in, say, roughly a 3-6inch radius) that can result in images that radiologists deem unusable for making a diagnosis.
I found a bunch of posters here, but I could not find the exact one that you mentioned:
https://www.ismrm.org/19/program_files/DP02.htm
Maybe lost now? Or a different page?
[1]: https://www.audeze.com/blogs/audeze-journal/press-release-fo...
Very vague explanation of how they work, and that link in the middle - I suspect that is the entire point of the press release.
> The CRBN headphones are integrated into the Lumica AV system from SMRTImage that provides images and movies
Maybe you can get more info out of them: https://www.smrtimage.com/
So after the claustrophobic panic subsided and I realized I was left in there with nothing but the loud machine and my own thoughts, I decided to listen to the machine as if it were music.
I found it supremely hypnotic and trance-inducing, almost meditative. I'm a big fan of deep and hypnotic techno, so the rhythmic MRI sounds were right up my alley. I'd probably have enjoyed it more with earplugs though.
I haven't looked to see if anyone has actually tried to make music with the sound or not.
That was a golden opportunity to experience ambient music in the most historically authentic way possible!
Listen to Brian Eno's story of what inspired his 1978 album, "Ambient 1: Music for Airports":
https://www.synthtopia.com/content/2016/01/05/brian-eno-tell...
Some of the pulse sequences are rhythmic and I find the entire thing somewhat meditative, but there are many other places I'd rather be.
Most (all?) vendors suggest this - they get well over 100db and the vendor headphones are pretty crappy.
Source: Radiologist (and personal experience in the bore)
I thought they would do it all the way through, but then I suddenly heard the pump start halfway through the procedure and a slightly cooler fluid running up inside my arms.
Also, I accidentally left my wedding ring on (I informed them, they were not interested in the slightest). My right felt hot during the scans. Not painful burning hot, but warmer than body temp for sure.
Loose or easily dislodged materials. My belt buckle was ok to keep on. Had to empty my pockets, take off my ring, metal piercings are disallowed.
You don’t want gobs of belongings piling up on your magnet, and you don’t want something large enough to pin the human between it and the magnet. The first scenario is quite expensive to rectify. The second is quite expensive, quite painful, probably fatal, and certainly traumatic.
The American College of Radiology say the below [1].
‘it is advisable to require that the patients or research subjects wear site-supplied MR Safe scrubs or gowns in place of their own clothing and undergarments in the region undergoing direct RF irradiation.’
Slightly odd - this appears to be about burns rather than projectile risk. Anecdotally, sites that don’t change patients have more accidents.
[1] https://www.acr.org/-/media/ACR/Files/Radiology-Safety/MR-Sa...
I'd guess the tube is longer in an MRI, though.
I bought a kind of unusual type of headphone from aliexpress a little while ago, that essentially consists of an induction loop you wear round your neck and tiny magnets you put in your ear, I'm somewhat scared to try them out as I don't especially want them to get stuck in my ear.
There is the odd burn - rare, and mostly preventable. Burns are the most common class or MRI injury.
I’m an MR tech.
They were awful.
Would they sound better if they used a liquid instead of air for the conduction?
I did wonder on my last flight if I could use SDR & android to listen in.
I wouldn't be surprised if the channel selector wheel was a simple mechanical acoustic coupler rotating to connect or cap upstream source tubes. I remember it as well flying in the late 80s or early 90s.
I see it is simple, but I wonder, would it be possible to use different sound medium ("conductor")? Some liquid, water perhaps? Would elasticity of the tube eat more signal than is lost in the air? Too heavy? Leaky? Questions…
