“Soft” materials, like heavy blankets, fabric and fiberglass, have loads of nooks and crannies, which sound tries to “fill”.
The more surface area a certain material has the better absorber it will likely be. The absorbed sound energy has not vanished, it’s actually been converted into kinetic (vibration of a solid material) and thermal energy (heat due to friction within a porous material) or has simply passed right through the material (transmission). When sound waves meet a room surface such as a wall, ceiling or floor, some of the sound energy is reflected back into the room and the rest is considered to be “absorbed”. However, let’s delve in closer and decipher what is actually usable information, and what is just marketing. On the surface this sounds like an extremely efficient product. We recently encountered an acoustical ceiling tile which was said to “absorb 50% of sound”. It should not be assumed that something which sounds technical is, in fact, backed up by proper testing. Also, given sheer volume of information available on the internet, it is perhaps unavoidable that some info will be incomplete or simply incorrect. In both scenarios, it is important to know which data is relevant and helpful. These are two separate acoustic issues which require separate solutions. If the problem is sound passing in between spaces, like offices or apartments, then isolation treatment is required. In an overly reverberant auditorium, absorptive treatment is needed to reduce echoes and improve speech intelligibility. In order to make informed decisions about acoustical treatment, it is vital to know the difference between materials that are meant to absorb sound within a room and materials that are meant to block sound from leaving or entering it. Part 1: Acoustic Terminology – Sound Absorption vs Sound Isolation In this series, acoustician Cameron Girard of Acoustics First® hopes to help you distinguish between what’s useful and what’s not. This flood of information can seem intimidating, especially to beginners. For anyone new to the world of acoustics, there is a multitude of terms, coefficients and numbers that are thrown around.
0 kommentar(er)
