Physicists Achieve Perfect Acoustic Absorption

Megalith

Megalith

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Does this mean that we’ll get earplugs that can truly block out all sound? I could really use a pair to block out my annoying neighbors.

In a paper published in the Applied Physics Letters this week, the Hong Kong researchers describe a rather more active absorption system (but not totally active) composed of two resonators, both of which are tuned to the same frequency, which is itself "impedance-matched" to the background medium, e.g. the open air or whatever surrounding the acoustic absorber. The result is sound-killing destructive interference.
 
I wish all restaurants would use this. I can't stand to hear other people, especially loud kids when we go out to eat.
 
Good for research purposes, but not for anything to do with every day living. Have you actually been in a real sound isolation chamber? You'll go fucking crazy in about 30 minutes.
 
Grahamkracka said:
Good for research purposes, but not for anything to do with every day living. Have you actually been in a real sound isolation chamber? You'll go fucking crazy in about 30 minutes.
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This. I went in an anechoic chamber when I worked at Nokia. It's weird as all hell. I started to feel sick.
 
Grahamkracka said:
Good for research purposes, but not for anything to do with every day living. Have you actually been in a real sound isolation chamber? You'll go fucking crazy in about 30 minutes.
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The extreme anti-social person's dream come true!

Actually, I would love to try a sound isolation chamber. Might actually be able to hear myself think then.
 
pothb said:
How does that solve the problem of having food from a restaurant?
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GrubHub? or any number of other restaurant foods to your door?

Or if you care that much about people's kids being too loud, go to a restaurant that typically doesn't cater to kids.
 
sfsuphysics said:
GrubHub? or any number of other restaurant foods to your door?

Or if you care that much about people's kids being too loud, go to a restaurant that typically doesn't cater to kids.
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Dude also complained about people talking in general. Restaurants are loud, with the exception of the super fancy kind. People like to talk during meals, especially when eating out. Sorry society at large can't conform to one person's antisocial behavior. Like I said, if he can't deal with it...then stay the hell home.
 
would LOVE this, make my own general noise is fine, but time and time again live in places where people stomping and slamming shit constantly, would be great to have earplugs, wall coverings or whatever that could mute some if not all of it, granted if it is to expensive that wouldnt be good either.
 
Grahamkracka said:
not for anything to do with every day living
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totally disagree, apart from lab testing and other mechanical scenarios, acousticians can use absorption strategically along with reflection/diffusion to make spaces sound more pleasing. There are also applications beyond normal human-hearing frequencies.
 
nothing saying one could not use this in say a vehicle, engine compartments, factories, planes, maybe even speakers and the like etc Youn might be hinting at some of those possibilities, the sky is the limit, narrow minds only see narrow solutions, but those that look for a problem (example DOORS that always have a harsh clack or thud sound to them) might see this as being a very valuable solution.

Hell I would use it for doors, as that sound drives me nuts, folks either slam them or do not turn or lift the damn handle :(
 
boomboy2k1 said:
Take a couple of sharpened pencils and stab them into your ears and be done with it. ;)
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knowing my luck it would just hurt. Thanks for that mental picture though :D I sometimes feel like doing so to tools that like to be blind to others just because they obviously are without a doubt the only ones that live in this wee little world in which only they truly matter.
 
Grahamkracka said:
No, not really. There is a reason it's been used as a form of mental torture to extract information. The US military also uses sensory deprivation, to include sound isolation, in SERE training. I can tell you from experience it really does make you feel crazy after a while.
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Fixed
 
Right, anyone who wants this in their house, ever considered:

1. You will never hear someone break into your house

2. If the said someone breaks into your house is a psychopath, your screams will never be heard

3. If something wrong happens that is usually accompanied by sound (such as gunshots, breaking glass, etc) you will never hear it?
 
I'd gladly accept the compromise of not being able to hear a psychopathic intruder in the statistically unlikely event of that ever happening, if it meant I didn't have to listen to the statistically certain sounds of people in adjoining apartments walking around on hard floors in hard heels, slamming doors or playing shitty music at 4am.
I bet you're a gun advocate too, and based on the exact same argument. I can't imagine living in such an overwhelming state of fear that it influenced every decision I had to make.
 
chenw said:
Right, anyone who wants this in their house, ever considered:

1. You will never hear someone break into your house
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Again, you miss the point, assuming it will be only used to kill all sound completely.

This is not true.

In residential applications it would probably be used to create a more pleasing and effective environment, so that you'd hear the intruder and other important ques but not your neighbors 4am subwoofer they left on after their household passed out from their lame Jimmy Buffet party.

This merely gives us more options as to HOW we control sound. It's not like some atom bomb that just obliterates everything causing our heads to explode from lack of sound movement, it could be used more surgically in specific places.

I can tell you from experience it really does make you feel crazy after a while.
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Yes, I've been in similar rooms and know the "pressure" they talk about. I think it's mostly because our ear drums are in less motion than they've ever been in and the constant motion in more typical environments are actually what helps decompress, or breathe, our equilibrium and other internal stuff near there... or something like that, I'm not an expert obviously, just a theory...
 
Grahamkracka said:
Good for research purposes, but not for anything to do with every day living. Have you actually been in a real sound isolation chamber? You'll go fucking crazy in about 30 minutes.
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I have, and I know some people who would go crazy, I liked it though, kind of weird how sensitive your ears really are and the sounds you can hear in your own body once everything else is removed.
 
Grahamkracka said:
Good for research purposes, but not for anything to do with every day living.
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Line a computer case with it to help shut it up? Put it in the walls between apartments to dampen the sounds of neighbors?

I dunno, seems handy...

Grahamkracka said:
Have you actually been in a real sound isolation chamber? You'll go fucking crazy in about 30 minutes.
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I've always wanted to try one of those. I'm extremely sensitive to noise, and no room ever seems quiet enough...
 
KazeoHin said:
It is heard, but it is not smelt. That is the freaky thing.
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LMAO, yep I could go for the sound deadening effect of stomps, slams, and general inconsideration of nearly everyone until of course you do it to them, hey maybe even when your not getting any at least you wont have to listen to others getting it, an actual quiet apartment complex would be AWESOME for a change, course probably would not be cheap so therefore very unlikely for it to happen, though I suppose any individual could at least muffle some things on their end provided the cost and form factor was not to prohibitive,

Wonder what ranges of sound it works with for example near the muzzle end of a rifle and stuff like that as well??
 
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