@Satur9 and @NiamhAstra
As far as i know you two currently have the most advanced tragus specific amp/coil equipment/knowledge/experiments.
Did you find anything noteworthy since this post happened?
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Since my update in December? No updates. I have an amplifier, but I haven’t gotten around to fabricating the belt coil. I’m not optimistic. I’ll try though to check it off my list. leumas95 seems to be more interested in house installations on the scale of an entire wall running of mains power
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I just got done with my proof of concept experiment. I ordered an amplifier like (like the one in this post)
and connected it to a random coil (a relay, in this case) i had laying around.
It works, but not very well. I have to put the relay directly to my ear in order to hear anything. Max distance is ~1cm. But hey, its progress and it motivates enough me to proceed.
Since i am planning on using it on the move, i dont think a necklace or belt is realistic with the amount of power available. I am probably going to experiment with a coil hidden somewhere near the ear.
My next steps are probably getting different sized coils with solid MuMetal-Cores and seeing what happens.
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You could always do the band of a hat. I thought about that but wasn’t willing to do it. A floppy beanie hat or something like that would work without being too suspicious
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instead of the investment in time/effort for the dental cement method, why not see if it works at all by gently biting down on a magnet, and see if the vibrations make it into one’s skull
I’ve been doing some thinking and very basic experimentation, and I had something I was wondering if it would be possible. .
Biting on it has already been tested, it kind of worked but not very well.
Just posting for the record. I have to get a head MRI, so I’m going to have my (fourth) tragus magnet removed. After that I’m going to abandon this quest. I personally have put a lot of myself into this and I don’t see a path where tragus magnets acting as wireless headphones have even half the convenience or quality of true wireless earbuds.
Maybe down the line I’ll get some form of implanted hearing aid if I can arrange for the surgery, but barring that I’m done. Good luck everybody
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Can anyone get his/hands on Maxum Implants
The MAXUM System is a hearing implant which includes a small magnetic titanium device and an advanced sound processor. The implant is placed in the middle ear with a simple, minimally invasive procedure and the sound processor is discreetly worn in the ear canal. The advanced sound processor uses electromagnetic energy to vibrate the implant which directly stimulates the inner ear or cochlea. This direct cochlear stimulation provides cleaner, crisper sound quality and more amplification without feedback.
http://www.ototronix.com/
Try Maxum hearing implant it’s basically a magnet attached to middle ear bones which vibrates in electromagnetic field and produces clear sound sensation without any feedback
Sounds like you’re marketing.
I don’t have any problem in hearing but i want these kind of implants to hear secretly
I will get the titan sensing biomagnet implanted in tragus what i have noticed is that though the sound is not clear and loud enough but if you push the tragus towards eardrum with your fingers it becomes clear and loud you can easily hear to music or conversations
I am also researching on implantable Bluetooth devices to make it completely covert
Thanks for reviving this thread.
Since my last update
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i tried to get in contact with several coil manufacturer to inquire about MuMetal-Cores. I included that i plan to use them for a tragus implant. Never heard back from any of them.
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i contacted Rich Lee, the original (?) tragus implant guy, about the fairly steep power requirements. His DIY solutions also -quote- “burned through batteries like crazy”. In the end, he and some other people settled on the Hero 800 amplifier neckloop. So i bought that.
About the hero 800:
If put the coil (3 winds) right around my ear, it works really well. Good volume, sound is a bit mushy, but that is a problem with how the titan is installed. Around the neck, volume drops considerably to a point where i would consider it useless everywhere but in very quiet places.
My next idea was to simply extend the wire to get more windings around the neck, since according to the formula B=uIN/l, more windings = stronger magnetic field? Im not good at coil design. Anyways, that didnt work because the resistance of normal wire is to low and the amplifier just doesnt turn on to protect itself. Turns out that the original antenna is made out of resistor wire (2 ohms total). Soldering both antenna in series to get the required resistance and length resulted in even worse volume.
So, once again, i tried brute forcing results by just throwing more power at it.
I still had this 50W amplifier from earlier.
It also requires a minimum resistance, in this case 4 ohms. So i put a high power resistor in series with the longer antenna.
This one is only rated for 25W, but since i couldn’t get the 50W version, this had to do. As it turns out, running double the rated power through a resistor is bad. It got really hot, so it is not usable anywhere near the body. The volume also didnt really go up. I assume thats because this is a wire wound resistor - so basically a coil - and thus messes with the actual neckloop coil.
Thats where im at currently. Power is still a major problem and im not optimistic that it will get any better. Without any active circuitry near/in the ear, the distance from the neck to the ear is just to big. Maybe optimising the coil could yield usable results, but again, i know nothing about coil design.
I may try again with a longer neckloop made from resistor wire to eliminate that resistor, but if that doesnt work, im out of ideas.
Like @Satur9, i now also dont see how
But there is still that niche area where you cant wear earbuds, like at work (retail) or on medieval festivals, where a fully concealed music player would be really useful.
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The Hero 8 looks like a good fit.
So ultimately for audio equipment all you’re trying to do is “impedance match” the 2ohms that the original coil had. To increase the amount of flux getting to your magnet, you’re going to want to minimize the height of the whole coil assembly ( l ), and increase the number of turns ( N ). In order to do that without dramatically increasing the resistance, you need to increase the conductor cross section (thicker wires).
One trick you could try that I only found out about recently is forming a stranded wire out of many individually insulated conductors. So basically you would take 28AWG magnet wire, cut 10-20 segments to the correct length (whatever the comfortable circumference to fit around your head is times the number of turns you want, say 6 plus a bit extra). Once you have all those lengths wire, you put the ends all together and solder them into a big glob. Then you twist all the wires together like you’re making a stranded wire all the way to the other end. Then you wrap this whole wire assembly into those 6 loops like you’re making your sound coil out of really thick wire, but it’s actually tons on individual wires isolated from each other with enamel. Then solder the other end. I would then tape all these loops together to make one big necklace.
The end result of this is that you will have a coil with a total resistance around 2ohms (probably more like 4ohms), but it will be comprised of 10-20 parallel inductors. So with 6 loops of 20 wires in parallel, you have the equivalent of 120 turns. The fact that they’re parallel inductors rather than one continuous one may have a multiplicative effect though. I haven’t fully explored it.
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While chatting over a few drinks a while back, @invalid_signal and I actually had a thought about this. Have you thought about placing the coil in the brim of a hat? This would place it a lot closer to the ear and still have the benefit of concealment if integrated well with the hat.
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Isn’t this similar to what they do to reduce the skin effect in the transformers of some of the larger switching power supplies?
Kind of makes sense. Since you now have loads of parallel wires/resistors (i intend to use resistor wire), the total resistance should be calculated as 1/R=1/R1+1/R2+1/…, which means that the individual resistances should be fairly high, correct? Or can this be trated as one big wire were every strand has the same resistance?
I do not wear hats, so i never explored that.
If you want only 2 ohms you don’t need resistor wire just use magnet wire because it has the insulating enamel. But yes the resistance will be the resistance of one strand divided by the number of parallel strands
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