Can color of the room change the acoustics?

I believe the traveling of sound can be analagous to the traveling of light since they are both waves (but I'm no expert on acoustics). Your main difference here is that sound is a mechanical wave that is created by oscillation air pressure. The color of a surface that comes into contact with oscillations in air pressure has no effect.

Light is an electromagnetic wave, so when it comes into contact with an electron, it can either absorb that energy or reflect it. This depends on the wavelength of the light. Black will absorb almost all visible light. I believe that this is true because black has a complete lack of electrons in higher states, so it will absorb almost any wavelength of light (although I'm not 100% sure about that statement).

 

Different colours of paint absorb and reflect different wavelengths of light. Likewise different types of furniture and furnishings (eg curtains) absorb sounds of different wavelengths. Remember those old bookcases with sliding glass doors? The glass sometimes rattled/resonated when different notes were played. If you have ever moved into an empty new house they can echo quite badly until the curtains are up.

 

The color in itself has no influence on the acoustics, as several people have already pointed out.

What may make a difference is if the paint changes the porosity of the material. Porosity has a great effect on sound, and open pore foams are often used as absorbers to damp reflections and resonances. If they were "sealed" with an air-tight layer of paint, then they could not be penetrated by the sound waves anymore (at least for certain wavelengths).

Heavy curtains, thick carpets, bookcases, and uphostery all absorb quite a lot of sound and have a strong effect on the acoustics of your room. Tiled floors, brick walls and large window panes hardly absorb at all.

In weakly absorbing rooms you can even get standing waves at low frequencies. E.g. between the floor and the ceiling.

 

Everyone knows red rooms are faster...er hang on maybe that's something else.

 

But color can have effect on temperature of room and that may change the acoustics. Or not? I would imagine that if you have say one wall black and one wall white, the temperature of air near the walls could be different and thus the speed of sound would be different. Not sure how the sound propagation would be affected though. I seriously doubt it would be anything measurable.

 

That is, after all, the whole point of "colors". They reflect and absorb different frequencies of light, not sound.

 

If you like learning from animations, http://www.animations.physics.unsw.edu.au/ has some good stuff.

In particular, for the differences between sound and light waves, here's two you should watch to get started. After the pages load, click on the play buttons on the right.

"Waves and Sounds" Introduction chapter 4 (Sound)

"Light" Introduction chapter 1 (Nature of Light)

 

Hey I've had a flick down the responses, I didn't look too closely to be honest but it looks like a few people are not wrong but just slightly off the mark with this one!

Yes the colour of an object will affect your perception of the sound it creates, as people have mentioned above different material properties will affect its reflective properties etc.. however our perception is not objective and it has been shown in several psychoacoustic studies that, for example, red trains sound louder than blue trains, when objectively they are creating the same Sound Pressure Level.

Companies like Genelec have known for years that green loudspeakers sound "more natural" than black speakers and those gold plated jacks you plug into your guitar don't objectively do anything! Its all in the mind, don't underestimate your brains ability to lie to you lol.

We should not be surprised by this as perception has long been known to be subjective and influenced by our other senses. Other good sound/colour examples are removing the high frequency crunch sound (using headphones and DSP) from chewing crisps makes them taste different, people think because they don't crunch they are stale. And brown décor in restaurants makes you want to eat more.

Having said that I should add that in room acoustics wall colour, generally, is not an important objective acoustical factor and it is your perception of the sound that might change (depending on the mood evoked by the colour for example) so I guess technically the acoustics don't change but your subjective appreciation of the acoustics might. Hope I cleared that up.

 

You're right that the speed of sound does increase when the temperature goes up, and 10°c can change the speed of sound by a few meters per second depending on other factors, not least pressure. However, firstly; temperature in a normal room will not vary enough from place to place or from time to time for this to have a factor on perception and I think you're being slightly miss led by the idea that black paint will be somehow hotter than white paint. Stephen Fry put that one to bed many QI episodes ago lol :)

Ben.

 

Yeah I know, but given the question was basically does colour affect sound I thought it would be worth mentioning, because it does lol. I do appreciate that it was a little off the subject of purely objective room acoustics. Thought it was quite interesting though, worth knowing and at least slightly relevant :).

Ben.

 

Hey Guys,

I know this has pretty much been put to bed now but for those that are interested, and for the sake of not looking like I was making things up :), here is a link to a paper from Proceedings of 20th International Congress on Acoustics about the perceived loudness of sounds when confronted with images of red and green trains.

http://www.mmk.e-technik.tu-muenchen.de/publ/pdf/10/10fas3.pdf [Broken]

Last time I wonder off topic, I promise.

Ben.