OT: Directional sense of smell and hearing in humans?

Sound: Ok, I didn't believe what I read that your brain can tell the direction of sound because one ear hears it first, I thought it was just volume. I mean detecting 2/3rds of a millisecond?! But I proved myself wrong - if you load your favourite piece of music into Audacity (a free sound editor), you can delay one channel (I delayed it by 0.68ms, the time taken for speed to travel the distance between my ears). Now listen through headphones. Although the same volume is in each ear (easily proved by pulling one earphone out), it sounds like it's entirely in one ear. Volume has the same effect, if I then made the other side 6dB louder, it went back to sounding like it was in the centre. I wonder why your brain uses both timing and volume?
Smell: This I can't believe though, and I don't know how to prove it except by experience. If you walk into a room, you have no idea which way a smell is coming from, yet I've read claims that you sense the smell through each nostril seperately and time it. A dog maybe, but surely not a human. I've never been able to work out where a smell is coming from without moving around the room and sampling different parts of it.
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Jimmy Wilkinson Knife wrote:

Do fuck off Hucker.
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Cant be volume when you know that something is off to the left a bit from where you are facing.

Yeah, interesting what we can do like that.

Because that's the way we evolved when something shows up that likes to eat humans etc and helps with hunting too.

More likely by how the smell varys as you turn your head.
Shouldn't be hard to prove by using those things they use in hospitals and ambulances to give you more oxygen, with each nostril with its own feed and then varying the amount of smell added to the air to each nostril.

Dogs basically shove their hose where they thing the smell is coming from.

Cant say I have tried doing anything else.
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That would make a louder sound to your left ear,m as your head blocks your right ear a little.

I would have thought volume was enough.
So do you know how surround sound works? That must do something clever with timings.

But how would one of us prove it?

Indeed.

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Not when its just off to the left a bit from where you are facing.

Nope, most obviously when its just off to the left or right a bit from where you are facing.

Yes.

Not clever so much as using the appropriate timing.

That way, by delivering the air to each nostril separately and varying the amount of smell to each nostril individually.
Those things are available for peanuts on ebay.

My alsatian used to shove his nose in male crotches, never could get him to stop doing that didn't go down to well when out and about taking the dog for a walk. He hated collars so I never used a lead.

I don't.

Nothing left on the plate.
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Surely the difference in volume is easier to detect than the minute change in timing that would result from the shallow angle you're suggesting.,

I'm interested in how they make a sound be behind you instead of in front of you. From what I've read very few can detect that without being familiar with that exact sound. Something to do with the shape of the ear canals.

You do it then.

Most dogs smell crotches. Presumably they're checking if you're in heat.

But you've eaten your own tongue aswell?
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Maybe not when its done by evolution, those that do it better surviving better than those that don't.

That has to be by timing rather than volume.

Don't believe that with common sounds you hear every day. Even an unusual vehicle approaching, you normally know if its coming up behind you or towards you even if you can't see it, effortlessly.

Cant see how that could do it.

No thanks, not interested enough to bother.

Not so obviously, but that may just be that he was much bigger than the average dog and so easier for him to do that.

Not with males. Its just the usual thing that all dogs do, decide who you are based on how you smell.
He never ever did it to me, just visitors etc.
Presumably just working out who they were, tho he did it even with visitors that showed up every day.
Very smell obsessed dog. He insisted on having a good close sniff of my dinner as soon as I put the plate on the table. Never attempted to grab any of it, but insisted on having a good sniff of what I was having every night.

Never ever do that.
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On 06/06/2018 00:23, Rod Speed wrote:

I've always assumed you do it by turning your head while the sound is present, which is why very brief sounds are hard to place.

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I'm not convinced, particularly with the very brief sound you get with something falling. I never have any doubt about whether that was in front of me or behind me etc.

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Hi, its phase and volume for hearing. However as you will also realise simply using headphones and a dummy head for microphones tends not to work very well and makes the room sound far more echoy than just your ears do. There is a lot more going on with real ears on your head than meets the , erm ear!
I don't think its really fully understood even now. You can of course mostly also hear if a sound is behind you. Tests with volunteers with their head in a clamp suggest that tiny movements of the head made automatically do the job of testing for in front or behind something that is of course lost if you use headphones and microphones. As for smell no its not directional. Who said it was? Most dogs like drug detection dogs etc sniff and try different directions moving around a room.
If you can get hold of a copy of a JVC recording called adventures in Binaural its worth a listen on your headphones. However don't listen while walking about or cycling. Brian
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Brian Gaff wrote on 06/06/2018 :

https://www.discogs.com/No-Artist-Adventure-In-Binaural/release/2747277
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