I randomly got reminded of a friend I had back in the early 2000s who had an obsession with a certain type of picture...

catgirls in headphones.

and the reason is... think about it for five seconds.

how does it work?
Those are human headphones, designed for human ears.

Catgirl ears are not located there, as you can see.

But there are ENDLESS pictures of catgirls wearing headphones.

I like this one because she looks vaguely annoyed and embarrassed.
and maybe that's because she just realized that these headphones won't work for her

This one has the headphones sorta coming off, so you can see human ears underneath, which just raises more questions

There's a lot of them where she's wearing the headphones around her neck, possibly because the artist started to draw it and went WAIT A MINUTE

Ahh, yes, earbuds.

in your human ears.
The ones you have in addition to the cat ears.

I've not found a picture yet, but there are pictures with catgirls wearing earbuds, and they just stuff the earbuds into their ear-fluff.

and here's a picture (thankfully on twitter) which has a catgirl wearing specially-designed catgirl headphones! https://twitter.com/rinrin_desu_/status/1252536166735384578

one thing I'm surprised I haven't seen yet:
You know how there are headphones which have catgirl ear decorations on them?

surely someone has drawn a catgirl wearing those, for maximum stupid.

And here's a catgirl trying and failing to use human-style headphones on cat ears

And here's an example of one that's clearly been designed for catgirls.
It's a sort of headband with pop-up speakers

And it's unisex too.
There are catboys wearing headphones, too!

(and by catboys I mean Kagamine Len. They're all Kagamine Len)

and another catgirl having to adapt human-style headphones to work on cat ears

One solution is apparently "put them on upside down"

and there's this weirdness.
These are like... quadraphonic headphones?
So I guess this catgirl has cat and human ears, and is wearing special headphones that play into both of them?

And the picture, uploaded to Danbooboo 14 years ago, is I think one of the initiating images.
This is what set my friend off on their Quest.

(Amusingly, this image was uploaded by another friend of mine from the same IRC channel)

It's not just an anime thing, of course.

And u/raymondcripps, who is making a videogame featuring a catgirl, drew this to explain how the catgirl wears headphones:
https://www.reddit.com/user/raymondafcripps/comments/i2s22d/im_settling_this_once_and_for_allhow_gabi_wears/

so I can't locate two pictures I wanted to include in this thread:
1. catgirls with earbuds stuffed into their cat ears
2. catgirls wearing a cat-ear-headphones

but I went all over danboofoo with rating:safe on and didn't see them, so either I missed them, they're not there, or they're all marked explicit.

so I'm giving up now.

here's another example of custom catgirl-headphones that assume catgirls have four ears: https://twitter.com/demize95/status/1338304159360184322

anyway I'd like to take this moment to confirm that I really do mean "a friend" when I say that a friend was obsessed with this issue. I wasn't euphemistically referring to myself.

I'm fine with you assuming I love catgirls, but I don't so it's not useful to be sent catgirls.

Send floppies instead.
Although catgirls with floppies are fine too.

Anyway if you are drawing catgirls or making some setting which has catgirls, please take a moment to think about how their headphones work.
(And the larger issue of how their ears work. 2 ears or 4?)

although I suppose it's fine to not think about this if catgirls have just been invented in your setting.

like if magic crystal explodes tomorrow and half the population suddenly has cat ears, it's gonna take a while to design some new headphones for them.

but if the catgirls have been around for a while, there'd be products designed for them, and headphones would definitely need to be different.

although if you assume catgirls have 4 ears and are happy with just listening to music in their lower ears (ie, not using them for noise-canceling), that'd work?
assuming their cat ears don't get in the way of the headband.

I'm also surprised I've not seen any catgirls wearing apple airpods

The anime Elfen Lied solved it in a weird way: The catgirls have human ears, and their cat ears?
they're not ears. They're horns... They're made of bone.

Also a few people have pointed out that Judy Hopps from Zootopia wears earbuds at one point.

Which makes sense, yeah.

I haven't seen Zootopia yet (because I have a vendetta against it for stupid reasons) but that's the part I'm most interested in: the world building of how you'd design things in a world where there's a bunch of different species with different body types living together

There are stock photos of robots wearing headphones, but I can't find more because googling "android headphones" is pretty useless.

This seems to make sense, but I'd love to see someone draw it where the robot is like "why?" and just plugs in an aux cable.

which is kinda something that actually exists.

You know there are people walking around who don't need headphones or speakers to listen to music?

There are Cochlear implants which have bluetooth support. You can just pair your implant to your phone.

The interesting thing about this is that it means you can listen to music without it at any point being actually "sound", as in sound waves.

Because Cochlear implants aren't just like tiny implanted speakers for your inner-ear. If they were, they wouldn't be as useful for people who have certain types of hearing loss.
They instead completely bypass your eardrums and the cochlea.

So instead of stimulating the parts of your ear that hear (the parts that convert sound waves into electrical signals), they go directly to the cochlear nerve and stimulate it directly.
So it's closer to an aux cable than a hearing aid.

And normally your Cochlear implant has microphones and sound processing that turns external sound into electrical signals.

But if you're using bluetooth, you can have a device that takes digital files, turns them into digital signals, transmits them over wireless, your implant receives, processe, and wirelessly transmits them to your internal implant, which causes signals to be sent to your brain.

there are no sound waves involved here. At no point is the air waving. There is technically no SOUND here.

amusingly if you're listening to electronically composed music, there may never have been any "sound" involved, because it was generated from synthesized samples, not things captured from microphones.

it doesn't even just have to be synth stuff. Electric guitars also create "sound" which doesn't involve the air moving... they're not just using microphones.

They instead work by having a permanent magnet and a detection coil, and the string becomes magnetic from the permanent magnet, then the coil detects the changing magnetic field from the string moving.

This does mean that you could play an electric guitar in a vacuum. So if you want to stage a rock concert on the moon, this is how you'd do it.

You would, however, have to re-tune it.
The strings would move faster without air resistance, so the pitch would shift up.

BTW an interesting side-effect of how electric guitar pick-ups work is that they're effectively directional antennas, and we're surrounded by 50hz/60hz electrical noise at all times, because of AC power, so a guitar is always going to be picking up that noise

This is fixed with a "humbucker", which is why electric guitars usually have that distinctive double-set of pickups placed next to each other.

The way they work is that they are two sets of coils, rotated with opposite polarity.
The external noise from AC hum is equal in both coils, but since one is backwards, it cancels itself out.

but at the same time, the string signal is not inverted, so it gets doubled instead of canceled.

All this applies to magnetic pickups, which are the most common type for electric guitars.
There are other types!
Piezoelectric pickups work by sensing the vibration of the guitar itself, and there's also electrostatic pickups which instead use capacitance instead of magnetism

and apparently there have been a few pickups which are optical: they use a photodiode and an LED to sense the string's vibration using light.

and of course you can just put a microphone on your guitar.

like a caveman.

(My dad's a guitarist who has spent his retirement building electric guitars so I picked up a bunch of this despite having no musical ability)

I've not asked him what type of a guitar a catgirl would use.

I wonder if they have claws they could use instead of a guitar pick?

https://twitter.com/Tirrelous/status/1097219650868396032