14 ms·
How do MRI Headphones work? (2022)
- jlarocco 3y agoThese are popular with two-way radios, where they're called acoustic tube earbuds. I'd guess the tube is longer in an MRI, though.
- rjmunro 3y agoTV presenters often use them; presumably the clear plastic tube are supposed to be harder to see.
- riffic 3y agotldr it's a pneumatic tube like a stethoscope. these used to be used within aircraft as well for inflight entertainment.
- lxgr 3y agoI've been on an airplane that used these! I think it even had a channel selector near the plug if I remember correctly (it's been a while).
- riffic 3y agoEDIT i'm wrong the speaker was inside the armrest. 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.
- denton-scratch 3y ago> a simple mechanical acoustic coupler I get what you're saying, and I think that's plausible. But as far as I'm concerned, an acoustic coupler is/was a type of modem, into which you plugged an ordinary telephone handset. You had to have a telephone that had hemispherical mike and earphone; it didn't work with e.g. a trimphone. Expected performance: 9,600 bits-per-second.
- riffic 3y ago"coupling" then, whatevs. lemme see if I can dig up a patent number for the channel switcher wheel and put this pondering to rest. seems the inventing corporation is still around haha https://avidproducts.com/2023/12/08/celebrating-70-years-of-avid/ https://avidproducts.com/2023/12/08/celebrating-70-years-of-...
- throwway120385 3y agoYep right next to the ashtray.
- ortusdux 3y agoI remember being able to select the pilot coms. I was nervous on my first flight as a kid, and it was very calming to hear the preflight checklist and ATC communication in the classic pilot cadence. This was pre 9-11. I did wonder on my last flight if I could use SDR & android to listen in.
- lxgr 3y agoYou can just use LiveATC on your phone these days, since many flights now have gate-to-gate Wi-Fi. I think it's not allowed to actually operate a radio receiver on an airplane in the us: https://travel.stackexchange.com/questions/2322/can-i-listen-to-air-traffic-control-on-a-flight https://travel.stackexchange.com/questions/2322/can-i-listen... Some airlines might still have the "listen to ATC" feature available, but in my experience, it's the pilots' decision whether that's available or not, and I've only ever been able to use it on a United flight once. Sirius XM on JetBlue also has an "ATC channel", but I've only ever heard silence there, and I'm not sure if that's a similar thing (i.e. sourced locally), or just a random ATC feed from somewhere in the country relayed via satellite.
- deleted 3y ago[deleted]
- doctorhandshake 3y agoI used to love trying to surreptitiously unplug my traveling companions’ headphones so I could blow into the end of the tube. Never once pulled it off.
- myfonj 3y ago> The sound is transported along the tube via air — a very simple solution. Though this also explains why they sound absolutely terrible. 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…
- focusedone 3y agoThis guy also has a post about the hierarchy of socks and underwear which resonated with me. https://tomlingham.com/articles/an-unfortunate-hierarchy-of-socks-and-underwear/ https://tomlingham.com/articles/an-unfortunate-hierarchy-of-...
- thisgoesnowhere 3y agoInteresting how different people's minds are. 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.
- adolph 3y agoFILO is not the standard method of maintaining one's stock of clothes? How else does a person mange wear leveling?
- throwway120385 3y agoI wear whatever makes me feel good.
- edward28 3y agoSimply pop from the bottom of the dresser.
- djhope99 3y agoI thought these were a nice idea when I had my MRI the other day, little did I know that I would barely be able to hear anything over the noise of the MRI machine. Ear plugs were better, kept out the noise of the MRI machine and let me drift into a trance.
- dylan604 3y agoWhat was your experience with the MRI like? Specifically, did you "feel" it? I've had my knee scanned for ACL damage, and have spoken to a few other acquaintances that have had scans as well. We've all discussed having some sensation in the exact part of the body being scanned. We all just happened to similar sports based knee injuries. It was just the slightest of tingling, but noticeable. Definitely not painful or anything scary. Was it just psychosomatic? Very possibly, but it's interesting that we all experienced it.
- tgv 3y agoMRI can cause a tingling sensation. Apparently, it can be quite noticeable when you make a loop, e.g. with your arms. See peripheral nerve stimulation.
- dylan604 3y agomake a loop? wouldn't that require breaking the cardinal rule of not moving during the scan?
- green-salt 3y agoFor my knee scans I could move into a position that was comfortable for me which actually I think was arms folded across my abdomen, but then you just do not move while the imaging is happening, which will have a distinct sound.
- secretsatan 3y agoI had a head one done, it was very noisy, but the thing I found most uncomfortable, or rather, disconcerting, is when they injected the tracing fluid. 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.
- cuonic 3y agoThey also use a similar mechanism for the "get me out of here ASAP" panic button [0] that staff place in your hand and tell you to squeeze if required, all it does is detect a change in air pressure on the other end of the tubing. [0] https://www.mriequip.com/store/pc/MRI-Non-Magnetic-Magnalarm-Patient-Panic-Alarm-p295.htm https://www.mriequip.com/store/pc/MRI-Non-Magnetic-Magnalarm...
- DennisP 3y agoMy house came with a button like that for the garbage disposal. Previous owner didn't like the idea of using an electrical switch with wet hands.
- jplona 3y agoI believe this is required by code in some places, depending on the location of the switch. Mine is inset into the counter top, so plenty of opportunity for water to pool around it which I think would rule out an electrical switch.
- DennisP 3y agoMine is also in the countertop, makes sense that code would require it in that case. Previous owner didn't like the idea of wet hands on a wall switch.
- Terr_ 3y agoI sympathize with that, more than once I've eyed mine's regular-light-switch and thought: "Surely the remaining water on my hands has too much surface-tension to go through any of those tiny gaps in the plastic... Right?"
- Aachen 3y agoA button for garbage disposal before you have a chance to dry your hands? What does this button do, activate some pneumatic tube system so you don't have to carry trash to the bin?
- FriedPickles 3y agoI was intrigued to see a lady at the crosswalk the other day wearing earbuds with thick tubing instead of wires. Googling it, I discovered they were "EMF free headphones". Apparently enough people think electromagnetic radiation in the ears is a problem that there are now dozens of these headphones on the market that put the driver half way along the cord, with tubes proceeding to the earpiece.
- edward28 3y agoIt would be a real shame if EMF could propagate.
- 77pt77 3y agoAs long as it's slowly maybe you can catch it. It it was at the speed of light we might have a problem.
- gumby 3y agoTo be fair, EMF is 1/r^2 so the transducers (speakers) are indeed far from the ear. Not that they need to be, but...
- jollyllama 3y agoThey're also more durable; i.e. resistant to running over the tube portion with a chair.
- Aurornis 3y ago> Apparently enough people think electromagnetic radiation in the ears is a problem 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.
- snakeyjake 3y ago>The only headphone tech that I was aware of or that I'd ever really considered 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.
- Vitaly_C 3y agoYes— there was a time where the free headphones were this style and you could bring your own electrically conductive headphones (with the right adapter, since it had separate RTS jacks for left and right channels) to enjoy a slightly better and louder sound quality
- mlfreeman 3y agoI remember putting my ear up to the little holes and faintly hearing the audio even without anything plugged in.
- treve 3y agoI've never heard this before! When I started flying it was just the 2 mono jacks that you still see on planes that haven't been updated (always wondered why it wasn't just a stereo jack) 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-airline-headsets/ https://apex.aero/articles/sound-tube-surprising-history-air...
- chriscjcj 3y agoIn my "maybe I'll need it some day" pile, I still have the two-mono-plugs to one stereo jack adapter I bought at Radio Shack so I could stick it to The Man. I think I only used it half a dozen times.
- HeyLaughingBoy 3y agoI bought a BLE wireless headset last year that came with one :-) No idea when I would ever need it!
- lynx23 3y agoAhh, memories. Roughly 20 years ago, I took part in a research experiment which had as its aim to figure out which brain areas were involved when a blind person reads Braille. TL;DR: They had a hypothesis, which was mostly confirmed. It happens in the visual cortex. Anyways, back then, MRI was still newish tech. FMRI wasnt used much in typical medical settings, but for research. As part of the deal, the MRI technicians did share a lot of gossip and random knowledge during the rather long preparation times. Long story short, this is when I learnt about the tubed earphones. And all the other mechanisms which were constructed to transport the braille strip wthout operating a real motor inside the magnetic field... Was almost worth the 4 hours of having to absolutely lie still...
- koliber 3y agoCompletely tangential story. A few months back I was getting an MRI. I stashed my belt, coins, keys, and phone. The machine started its clicking and thumping when I realized I had my wedding band on my ring finger. Immediately my mind raced to a video I once saw of an MRI machine propelling a fire extinguisher across the room. I braced for my finger to be torn off while I slowly took the wedding band off using only one hand. Luckily it stayed put through the whole scan and nothing happened.
- randlet 3y agoIf it was ferromagnetic you would likely feel it tugging as you got close to the magnet. Gold, silver, titanium are ok in MRI. However, next time, the second you realize you have metal on your person you should immediately inform the techs rather than try to just hold onto it! Aside from the risk of injury, it can be a real pain to get stuck items off the machine.
- lostlogin 3y agoTaking off metal jewellery in the scanner is about the worst thing one can do - it’s then loose. It would be very unlikely to move from a clenched fist, even if ferromagnetic. However having it escape your hand isn’t that difficult. I’ve seen most these things play out. And as you say, it’s exactly what the call bell is for.
- dessimus 3y agoI forgot to take my tungsten carbide wedding band off as well for an MRI, nor did the MRI techs say anything. It was in the middle of the MRI scan that I realized it was still on and then my fingers on the ring hand kind of started to feel fairly warm, but not certain it that was actually the ring picking up magnetic energy or if it was psychosomatic, but no harm became of it. 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.
- ska 3y agoWhat you were experiencing was a) probably real and b) due to the conductive properties of the ring , not magnetic. 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 .
- denton-scratch 3y agoI haven't flown for many years; but I think I remember airline headphones that were connected to the seat-handle with a hollow plastic tube. They were awful.
- amelius 3y agoSo they work like a stethoscope. Would they sound better if they used a liquid instead of air for the conduction?
- timvdalen 3y agoI made the mistake of brining an episode of 99% Invisible to an MRI. The sound quality is so bad that you barely can't make out voices. It was excruciating to listen to something I could almost understand for that time.
- EnzymeFestival 3y agoWhat options exist for something superior? These headphones are awful
- astrodust 3y agoStimulating the audio processing part of your brain directly with the MRI machine.
- ricardobeat 3y agoElectrostatic headphones: https://www.audeze.com/blogs/audeze-journal/press-release-for-the-audeze-and-smrt-image-collaboration-for-crbn-electrostatic-mri-headphones https://www.audeze.com/blogs/audeze-journal/press-release-fo...
- Retr0id 3y agoMEMS https://usound.com/usound-introduces-patient-safe-mems-loudspeaker-for-mri-compatible-headphones/ https://usound.com/usound-introduces-patient-safe-mems-louds... Datasheet (PDF) https://usound.com/download/achelous-datasheet/?wpdmdl=746 https://usound.com/download/achelous-datasheet/?wpdmdl=746
- roywiggins 3y agoYou can technically alter the sequence to make the scanner itself produce music. I don't know if anyone actually does this... https://pubmed.ncbi.nlm.nih.gov/26178439/ https://pubmed.ncbi.nlm.nih.gov/26178439/
- lakpan 3y agoHire a non-metal band to play for you in the room.
- DavidVoid 3y agoHigh-end headphone brand Audeze recently made an electrostatic headphone that works in MRI machines.[1] No air tubes needed and much better sound quality (and much more expensive). [1]: https://www.audeze.com/blogs/audeze-journal/press-release-for-the-audeze-and-smrt-image-collaboration-for-crbn-electrostatic-mri-headphones https://www.audeze.com/blogs/audeze-journal/press-release-fo...
- m463 3y ago> [Audeze has since made an audiophile version, called the CRBN headphone, read that story here.] Very vague explanation of how they work, and that link in the middle - I suspect that is the entire point of the press release.
- lmz 3y agoWell it says the headphones are sold by the MRI company: > 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/ https://www.smrtimage.com/
- anfractuosity 3y agoInteresting, sound kind of like a stethoscope. 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.
- birdman3131 3y agoI must be from a different era because a cup and string was well known as a kid as a way of transmitting sound. This is a very similar process.
- fluidcruft 3y agoOne of my favorite ISMRM posters that I saw in Toronto years ago was titled something like "a low-cost MRI-compatible communication system". It was really well written and you had to look at the photos to fully realize it was actually two Dixie cups connected by a string.
- throwaway2037 3y agoMan, you really nerd sniped me here. First: ISMRM means "International Society for Magnetic Resonance in Medicine" from here: https://www.ismrm.org/ https://www.ismrm.org/ 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 https://www.ismrm.org/19/program_files/DP02.htm Maybe lost now? Or a different page?
- fluidcruft 3y agoI'm pretty sure it was the 2008 ISMRM meeting (small chance it may have been 2003). I don't think it was actually submitted, because I couldn't find it in the proceedings even back then. I think whoever it was smuggled the poster into the hall and hung it among the others as a prank. I'm pretty sure the dead salmon fMRI poster was also there at the time but I can't remember if that was in the proceedings. The dead salmon fMRI did end up being published though and making quite a stir.
- jagged-chisel 3y ago> I'm not allowed to have any metals or magnetic materials on me. 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.
- roywiggins 3y agoAlso important: no fabrics with metal fibers. https://www.ajnr.org/content/34/5/E47.full https://www.ajnr.org/content/34/5/E47.full
- bpye 3y agoDoes this possibly depend on the field strength? I was asked to change into a hospital gown when I had an MRI a couple years ago.
- lostlogin 3y agoThis is standard practice at many places and should be standard everywhere. 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-Safety/Manual-on-MR-Safety.pdf https://www.acr.org/-/media/ACR/Files/Radiology-Safety/MR-Sa...
- fortran77 3y agoThis is exactly how headphones on passenger airlines worked several decades ago, until about 1990.
- aitchnyu 3y agoTangential, I saw an episode of House where he put a patient with medical implants into an MRI and they ran it for a few seconds till the burning was too painful. Was this realistic?
- tsol 3y agoI remember there was an episode where this happens with a prison tattoo-- some of them can contain heavy metals that react in an MRI.
- lostlogin 3y agoIt happens sometimes. I’ve been there for it with an infected filling (patient was unaware - they went to a dentist and reported back), with tattooed eyebrows and anyone with a cochlear implant tends to suffer (from the torque, not heating). There is the odd burn - rare, and mostly preventable. Burns are the most common class or MRI injury. I’m an MR tech.
- Traubenfuchs 3y agoOk, interesting, makes sense. Next, explain to me why the MRI machine does not... take itself apart? In an MRI machine without a cover you can see all kinds of micro and macro machinery, cables, fans, plating, sensors, magnetrons, pulse transformators, gun drivers... Pretty much each of those parts would be pulled through the room and get stuck to the MRI machine if brought in individually, or am I wrong? https://www.google.com/search?q=mri+without+cover&tbm=isch https://www.google.com/search?q=mri+without+cover&tbm=isch
- r2_pilot 3y agoThe engineers have accounted for this and appropriately fasten the individual components to the machine rather than bringing the parts in for assembling the machine while the high powered magnetic field is present.
- slowtokyo 3y agoSo how do the microphones that you use to talk to the tech in the MRI machine work?