Experts at the University of Bristol have discovered that the scales on moth wings act as excellent sound absorbers even when placed on an artificial surface, with the wings absorbing as much as 87% of the incoming sound energy. The effect is broadband
and omnidirectional, covering a wide range of frequencies and sound incident angles.

https://phys.org/news/2022-06-moth-winginspired-absorbing-wallpaper-sight.html

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On Wed, 15 Jun 2022 02:36:57 -0700 (PDT), Jimmy Two Shoes <coven@suddenlink.net> wrote:

Experts at the University of Bristol have discovered that the scales on moth wings act as excellent sound absorbers even when placed on an artificial surface, with the wings absorbing as much as 87% of the incoming sound energy. The effect is broadband

and omnidirectional, covering a wide range of frequencies and sound incident angles.

https://phys.org/news/2022-06-moth-winginspired-absorbing-wallpaper-sight.html

No. Sound absorption depends on the depth of the absorber with respect
to the wavelength of the sound. Moth wings may be good at dealing with
bats' sonar, but don't imagine that is going to translate into
wallpaper that can absorb 50Hz.

d

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On 15/06/2022 13:53, Don Pearce wrote:

On Wed, 15 Jun 2022 02:36:57 -0700 (PDT), Jimmy Two Shoes <coven@suddenlink.net> wrote:

Experts at the University of Bristol have discovered that the scales on moth wings act as excellent sound absorbers even when placed on an artificial surface, with the wings absorbing as much as 87% of the incoming sound energy. The effect is

broadband and omnidirectional, covering a wide range of frequencies and sound incident angles.

https://phys.org/news/2022-06-moth-winginspired-absorbing-wallpaper-sight.html

No. Sound absorption depends on the depth of the absorber with respect
to the wavelength of the sound. Moth wings may be good at dealing with
bats' sonar, but don't imagine that is going to translate into
wallpaper that can absorb 50Hz.

d

Use the same principle, but change the scale of the surface? Scales are
a few microns thick, so wallpaper would need to be a few millimetres?

--
Tciao for Now!

John.

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On Wed, 15 Jun 2022 15:17:39 +0100, John Williamson <johnwilliamson@btinternet.com> wrote:

On 15/06/2022 13:53, Don Pearce wrote:

On Wed, 15 Jun 2022 02:36:57 -0700 (PDT), Jimmy Two Shoes
<coven@suddenlink.net> wrote:

Experts at the University of Bristol have discovered that the scales on moth wings act as excellent sound absorbers even when placed on an artificial surface, with the wings absorbing as much as 87% of the incoming sound energy. The effect is

broadband and omnidirectional, covering a wide range of frequencies and sound incident angles.

https://phys.org/news/2022-06-moth-winginspired-absorbing-wallpaper-sight.html

No. Sound absorption depends on the depth of the absorber with respect
to the wavelength of the sound. Moth wings may be good at dealing with
bats' sonar, but don't imagine that is going to translate into
wallpaper that can absorb 50Hz.

d

Use the same principle, but change the scale of the surface? Scales are
a few microns thick, so wallpaper would need to be a few millimetres?

My sound absorber panels are 8 inches - four of gap and four of
rockwool.

d

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On Wednesday, June 15, 2022 at 5:37:00 AM UTC-4, co...@suddenlink.net wrote:

Experts at the University of Bristol have discovered that the scales on moth wings act as excellent sound absorbers even when placed on an artificial surface, with the wings absorbing as much as 87% of the incoming sound energy. The effect is broadband

and omnidirectional, covering a wide range of frequencies and sound incident angles.

https://phys.org/news/2022-06-moth-winginspired-absorbing-wallpaper-sight.html

______

This definitely would not work for a foam sales guy living
40m from the business end of a rock club housed in a
60 year old tavern building

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Jimmy Two Shoes <coven@suddenlink.net> wrote:

On Wednesday, June 15, 2022 at 7:53:33 AM UTC-5, Don Pearce wrote:

No. Sound absorption depends on the depth of the absorber with respect
to the wavelength of the sound. Moth wings may be good at dealing with
bats' sonar, but don't imagine that is going to translate into
wallpaper that can absorb 50Hz.

Marc Holderied (University of Bristol) was part of a webinar that discussed the findings:

https://www.youtube.com/watch?v=Oli4BZCU0qU

I think the idea here is that the path length through the moth wing is greater than the path length through foam or fibreglass batting, and therefore the thickness is less for a given turnover frequency. This is not an amazing breakthrough that will give us paper-thin absorbers, but it's definitely interesting and it could be a path to slightly thinner absorbers.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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On Wednesday, June 15, 2022 at 7:53:33 AM UTC-5, Don Pearce wrote:

No. Sound absorption depends on the depth of the absorber with respect
to the wavelength of the sound. Moth wings may be good at dealing with
bats' sonar, but don't imagine that is going to translate into
wallpaper that can absorb 50Hz.

Marc Holderied (University of Bristol) was part of a webinar that discussed the findings:

https://www.youtube.com/watch?v=Oli4BZCU0qU

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This may be news to scientists, but to me, it's just an extension of absorption and diffusion. I used to work fairly regularly on a sound stage here in Baltimore. The walls had been sprayed with cellulose, but the two story structure always had ring in
it. One day we had a shoot in which someone ordered a 20' x 20' silk on a square metal frame that was suspended above the talent and through which several lights shown. The silk was about 5' above the talent. I was booming with a Schoeps CMC641 below the
silk. The silk was doing a really nice thing for the sound. The talent's indirect sound had to pass though the silk to get to the room where they banged around a bit and worked their way back through the silk to get to my microphone. Bottom line: Less
room ring.

Back at my much more modest studio, I heard a difference when I hung my first muslin backdrop for shooting video. The room acoustics got tighter. Not dead, just tighter. Later on, when I hung a cotton green screen behind the muslin so I could have both
at the ready, the room got even tighter.

There's a 2 foot space between the back of the back drops and the wall. If you step back there, you can still hear what's going on through the muslin and cotton, but the reflections are obviously not as great. The back drops are floor to ceiling and run
across two adjacent walls. The backdrops have enough height to roll out across the floor, creating a fabric cyc wall. I also have wall-mounted absorption and diffusion panels mounted on the wall. I put them up years ago, and added the muslin and cotton
when I began shooting video. In effect, what I have is two large moth wing cyc walls.

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On Wednesday, June 15, 2022 at 2:37:00 AM UTC-7, co...@suddenlink.net wrote:

Experts at the University of Bristol have discovered that the scales on moth wings act as excellent sound absorbers even when placed on an artificial surface, with the wings absorbing as much as 87% of the incoming sound energy. The effect is broadband

and omnidirectional, covering a wide range of frequencies and sound incident angles.

https://phys.org/news/2022-06-moth-winginspired-absorbing-wallpaper-sight.html

While we're at it ... does anyone have any experience with acoustical paint? I recall reading about some U.S. Navy research about using ceramic microspheres in a thick coating, resulting in *some* acoustical and thermal attenuation.

"If you notice the *sound*, it's wrong!" ~ Roy W. Rising

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Roy W. Rising <rwrising@dslextreme.com> wrote:

While we're at it ... does anyone have any experience with acoustical paint= >? I recall reading about some U.S. Navy research about using ceramic micro= >spheres in a thick coating, resulting in *some* acoustical and thermal atte= >nuation. =20

There are a bunch of popular spray-on popcorn coatings, and they all produce
a little absorption and a little diffusion in the top couple octaves and although they are useful they are not the wonderful cure-all that architects without acoustical background seem to believe.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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On Fri, 17 Jun 2022 09:43:00 -0700 (PDT), "Roy W. Rising" <rwrising@dslextreme.com> wrote:

On Wednesday, June 15, 2022 at 2:37:00 AM UTC-7, co...@suddenlink.net wrote: >> Experts at the University of Bristol have discovered that the scales on moth wings act as excellent sound absorbers even when placed on an artificial surface, with the wings absorbing as much as 87% of the incoming sound energy. The effect is

broadband and omnidirectional, covering a wide range of frequencies and sound incident angles.

https://phys.org/news/2022-06-moth-winginspired-absorbing-wallpaper-sight.html

While we're at it ... does anyone have any experience with acoustical paint? I recall reading about some U.S. Navy research about using ceramic microspheres in a thick coating, resulting in *some* acoustical and thermal attenuation.

"If you notice the *sound*, it's wrong!" ~ Roy W. Rising

If you want to stop sound transmission to another area you need mass
and/or stiffness. And plug even the tiniest of air leaks.

d

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Don Pearce wrote:
=================

If you want to stop sound transmission to another area you need mass
and/or stiffness. And plug even the tiniest of air leaks.

** Confusion ( in the minds of the public) between sound absorption and blocking sound transmission has been rife for centuries.
You may need one or the other or both.
The former involves *quickly* turning the sound energy in a space into heat using soft materials.
The latter means containing the energy in a space.
Neither is ever simple.


..... Phil

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Scott Dorsey wrote:

Roy W. Rising <rwrising@dslextreme.com> wrote:

While we're at it ... does anyone have any experience with acoustical paint= >> ? I recall reading about some U.S. Navy research about using ceramic micro= >> spheres in a thick coating, resulting in *some* acoustical and thermal atte= >> nuation. =20

There are a bunch of popular spray-on popcorn coatings, and they all produce a little absorption and a little diffusion in the top couple octaves and although they are useful they are not the wonderful cure-all that architects without acoustical background seem to believe.
--scott

They're also a massive horror to remove. And eventually you'll have to.

--
Les Cargill

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