# Why is there a delay of about 10 milliseconds of vocals in L or R?

## Main Question or Discussion Point

Why is there a delay of about 10 milliseconds of vocals in one of the stereo outputs?

I heard, this is supposed to give you a sense of space. But our ears are just less than 1 foot apart, and it takes sound about 1 millisecond to travel 1 feet in air. Since our ears are not 10 feet apart, we never perceive the same sound in one ear more than 1 millisecond later than the other. So, what's the point in putting so long delays?

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Borek
Mentor
You mean SciFi vocals, or Fantasy vocals?

You mean SciFi vocals, or Fantasy vocals?
Oh, sorry. I thought this category is for ''SciFi & fantasy movies, TV, books, comics, art, games and culture!'' So I thought I might put question on music as well. Now I get that even the ''TV, books, comics, art, games and culture'' questions have to be based on sci-fi and fantasy stuff.

Is there a way I can move this thread in a different category?

Pythagorean
Gold Member
I would think 1 foot apart only works if you're wearing headphones. If it's designed for speakers, it's really more of a guess. And they're also assuming you're directly in the middle of the speakers, probably.

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Borek
Mentor
Honestly, no idea what category it is going to fit. Mostly because I have no idea what the question is about. I mean - I have never heard about the delay being added. But if it is, it just moves perceived source of the sound.

Pythagorean
Gold Member
It's a technique to make sound more real by simulating it as it would be in 3D. There's a demo that uses the algorithm with a clip of someone cutting your hair and it sounds/feels like the scissors are actually moving around your head.

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Pythagorean
Gold Member
Without using headphones though, I don't think it works near as well, you can't guess the position of everyone in the room or their distance from the speaker, making the geometry rather undefined. The haircut one I listened to with headphones was unsettling. I was scared my ear was going to get snipped.

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jtbell
Mentor
Is there a way I can move this thread in a different category?
I've moved this to the general "Computing & Technology" forum, because we sometimes have questions about audio/video systems and technology there.

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AlephZero
Homework Helper
1 person
I would think 1 foot apart only works if you're wearing headphones. If it's designed for speakers, it's really more of a guess. And they're also assuming you're directly in the middle of the speakers, probably.
Thank you very much. Yes, I didn't think about speakers actually. But the same sound reaching one ear, even when you're listening to music with speakers, at a delay of about 10-30 ms never happens in reality.

Somebody told me that it's intended to make the sounds sound ''thicker'' or ''wider'' or whatever. And another said, it helps the ''imperfect'' sounds sound less so.

I've moved this to the general "Computing & Technology" forum, because we sometimes have questions about audio/video systems and technology there.
Thank you very much for the correction.

It's a fairly standard music production "trick". See the "chorus" section in
http://www.sonicscoop.com/2013/01/14/all-mixed-up-delay-is-a-mixers-best-friend-by-jamey-staub/ for example.

It doesn't have to correspond to anything physically "real", so long as it fools your brain into hearing what the record producer wants you to hear.

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meBigGuy
Gold Member
You perceive the 10ms delayed speaker as being 10ft further away, increasing the perceived sound stage.

Spatial Enhancement is a hot audio processing topic, especially given all the Home Theatre systems out there now. For example, TI has chips for it:
http://www.ti.com/lit/ml/slyb185a/slyb185a.pdf [Broken]

Here is a pretty involved paper regarding a spatial enhancement technique:

Last edited by a moderator:
1 person
You perceive the 10ms delayed speaker as being 10ft further away, increasing the perceived sound stage.

Spatial Enhancement is a hot audio processing topic, especially given all the Home Theatre systems out there now. For example, TI has chips for it:
http://www.ti.com/lit/ml/slyb185a/slyb185a.pdf [Broken]

Here is a pretty involved paper regarding a spatial enhancement technique: