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Teach yourself to echolocate (2018)

(www.atlasobscura.com)
242 points Anon84 | 23 comments | 16 Nov 24 22:43 UTC | HN request time: 1.669s | source | bottom
1. almd ◴[17 Nov 24 04:02 UTC] No.42161878[source]▶
This is often used by audio mixing engineers and taught in a roundabout way at schools and studios. We think a lot about where thins “sit” in the mix. Proximity wise, and even height wise in a stereo mix. Eventually you learn how to locate things in headphones and it’s a really weird sensation when you realize you can do it. The kicker is we start out by simulating real environments in mixes, but then end up having to simulate what people expect from the medium as opposed to real life. For example something I learned doing video audio, if someone is writing something on a train, viewers expect to hear the pen on paper. But irl, there’s not a chance it’s audible. Explosions are always distorted because microphones end up clipping due to the volume, etc.

A great book on spatial simulation is The Art of Mixing by David Gibson. Older but forever relevant

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2. hackernewds ◴[17 Nov 24 05:04 UTC] No.42162108[source]▶
You went on quite many topics there. Could you expand on the proximity and height? Fascinating

The closest analogue I can think of is how due to practice now anyone can close their eyes and imagine typing entire essays how they know exactly where the keys are. Try it.

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3. high_priest ◴[17 Nov 24 07:04 UTC] No.42162470[source]▶
I have played alot of videogames & at some point identified, how can I guess, the source of sounds. Guess, because it's nowhere near actual approximation. Most often, source is guessed by context. E.g. The door knocking sound illusion, which was used to troll streamers.

Then you have directional localisation based on delay between ears, difference in volume & properties of reverberations. Things to the sides are going to arrive in either ear at different moment. Add source if first echo & you have confirmation that a sound is coming from either right or left. The more directly to the side is the sound, the bigger the delay between ears is, so you get approximate angle.

Now we consider sound muffling, caused by shape of our head & ears. Things in front are going to sound clearer in the opposite ear, than sounds from the back.

The same principle is used for detection of height. Things below are going to get muffled, things above will be clearer. In reality, feeling sounds with the whole body helps in source localisation, which can't be emulated with headphones.

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4. JoeyJoJoJr ◴[17 Nov 24 07:21 UTC] No.42162538[source]▶
There is a video for the art of mixing. It is indeed fascinating.

https://m.youtube.com/watch?v=TEjOdqZFvhY

5. vasco ◴[17 Nov 24 09:30 UTC] No.42163060[source]▶
> For example something I learned doing video audio, if someone is writing something on a train, viewers expect to hear the pen on paper

Just yesterday was watching Territory season 1 where the characters have an intense suspenseful, almost whispering "serious voice" conversation while standing next to a running helicopter, without even raising their voices which took me out of the scene.

So the question is, do viewers want it, or do know it all producers say people do and put it in?

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6. romwell ◴[17 Nov 24 09:53 UTC] No.42163148[source]▶
That's not at all what echolocation is. What you describe is locating the source of sound using binaural hearing (similar to how we can gauge distances using stereoscopic vision).

Echolocation is finding out distance to objects (not sound sources!) by sending a sound wave in a direction, and listening for echos that bounce back. Hence echolocation.

The only sound source is you.

It's a form of active sensing: literally how a submarine sonar works (or radar, for that matter). Bats do it, too.

This has very little to do with "locating things in headphones", as that is entirely missing the active part in the first place.

Then, locating sound sources using binaural hearing is not the same as analyzing the scattered echoes when the sound source is you (relative to yourself, you know where you are already!).

It's interesting that this is currently the top comment. I wonder how many people read the article before engaging in this discussion.

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7. planewave ◴[17 Nov 24 10:10 UTC] No.42163204[source]▶
This comment captures a lot of important detail about echolocation.
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8. Moru ◴[17 Nov 24 12:11 UTC] No.42163762[source]▶
When they say viewers want it, they mean just about 90% won't notice. Most people haven't been close enough to a running helicopter to understand.

I'm having problems watching movies at all, there is so many things breaking my immersion. :-)

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9. sandworm101 ◴[17 Nov 24 17:04 UTC] No.42165290{3}[source]▶
Ive seen a BBC doc that tested this. They had people use putty to change the shape of thier ears, resulting in an inability to judge the height of a sound. Given how differently-shaped ears are, as opposed to the inner structures which are virtually identical, this result points towards a learned skill rather than something genetic. We each must learn how our paticular ear shapes modify sound.
10. yazzku ◴[17 Nov 24 17:25 UTC] No.42165439[source]▶
> literally how a submarine sonar works

And dolphins and whales, no need to go to submarines.

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11. bestouff ◴[17 Nov 24 17:34 UTC] No.42165495[source]▶
I think what you mean is that all your examples don't work when recorded. But a human being in a train may hear the pen on the paper.
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12. dnh44 ◴[17 Nov 24 18:48 UTC] No.42166024{3}[source]▶
I once lived in a shared 4 story house and I always intuitively knew where everyone in the house was, even if they weren't being loud. You could just tell where everyone was based on how the house creaked in response to footsteps. We had someone new move in once who walked very quietly and it made me feel slightly uneasy because they were sort of invisible to my hearing.
13. kibwen ◴[17 Nov 24 19:17 UTC] No.42166285{3}[source]▶
> When they say viewers want it, they mean just about 90% won't notice.

Even more than that, they will notice if you don't it the "wrong" way that they've come to expect. This is called The Coconut Effect: https://tvtropes.org/pmwiki/pmwiki.php/Main/TheCoconutEffect

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14. Moru ◴[17 Nov 24 20:14 UTC] No.42166786{4}[source]▶
Ah, had no idea it had a name!

My clearest memory of that was me as a kid watching a Bond-movie where a sportscar makes a screaching sound when driving down a sandy beach. I turned of the TV and don't think I ever saw a full Bond movie after that.

The list on the page you linked had one thing that isn't toally correct though:

>The very specific (but entirely unrealistic) echoing thud that is heard when all the lights are turned on in a large spacenote .

That sound is realistic if it is an old building with the heavy type of power relays or whatever they are called. They do make that sort of sound if the acoustics are right. They could be set up with timers so they don't start the lights at exactly the same moment to prevent overloading the fuses.

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15. jacobolus ◴[17 Nov 24 20:32 UTC] No.42166955{3}[source]▶
Interestingly, it took until after the invention of SONAR for the theory that bats navigate by echolocation to be accepted. The theory that bats use hearing for spatial awareness was first proposed in the late 18th century, with experimental evidence, but was rejected by the scientific establishment for more than a century. People didn't know marine mammals used echolocation until the 1950s.
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16. romwell ◴[18 Nov 24 02:33 UTC] No.42169236{4}[source]▶
I didn't know this, but the intuition that a tech example will be easier to grasp than an example from biology was why I mentioned sonar before bats in the first place.

Fascinating to find out that the scientific community had this kind of bias as well.

17. yazzku ◴[18 Nov 24 03:17 UTC] No.42169439{5}[source]▶
The parent comment is obviously stupid and has already been down-voted, so HN is doing its job? There is no need to feed the troll.
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18. romwell ◴[18 Nov 24 03:50 UTC] No.42169573{6}[source]▶
>The parent comment is obviously stupid and has already been down-voted, so HN is doing its job? There is no need to feed the troll.

It's visible, and from my experience, it's not obviously stupid to many people, while being actively harmful.

This is not a trolling comment either, so I don't feel like "feeding the troll" metaphor applies. The "do not feed the troll" advice is usually given to not create opportunities for the troll to come and engage with.

Bigots are not trolls. When countered and having nothing to say, they shut down. Unlike trolls (who say things to simply provoke emotions), bigots want to feel in the right, and will abandon the conversations (and spaces) where that isn't feasible.

To stop the troll, you stop feeding them. When met with no response, trolls move on to something else.

To stop the bigot, you stand up to them. When met with no response, bigots feel emboldened, and do more of the same.

There is no need to feed the trolls. There is a need to stand up to bigotry.

19. romwell ◴[18 Nov 24 04:11 UTC] No.42169652{3}[source]▶
Thanks! I'm glad you found it useful.
20. tinix ◴[18 Nov 24 05:21 UTC] No.42169914{5}[source]▶
Have you never walked through sand and heard it screech or squeak? It's definitely a thing.

https://en.m.wikipedia.org/wiki/Singing_sand

21. romwell ◴[18 Nov 24 07:06 UTC] No.42170408[source]▶
You can absolutely hear someone writing in a room.

Whether it's audible on a train, depends on how insulated the train is.

I get the OP's point, but indeed this probably wasn't the best example.

22. webspinner ◴[18 Nov 24 18:37 UTC] No.42175451[source]▶
If you know how to touch type you should already know how to do this. I know for me it was a requirement in my 7th grade class.
23. quinnirill ◴[18 Nov 24 20:50 UTC] No.42176853{4}[source]▶
Surprisingly, it’s also present in live sports, see for example this article (in Finnish) about sounds in winter sports broadcasts: https://yle.fi/aihe/a/20-10005843