Soundbites No 3 – A nice row of trees is an effective acoustic screen: true or false?
As usual, the answer is not straightforward.
If we are looking at sound reduction in dB, then foliage is pretty poor at providing attenuation. So, if you plant a couple of rows of trees at the end of your garden to reduce the noise from that road, the change in sound level at your house is unlikely to be measurable or noticeable. Unless, that is, you use the trees to cover up a nice dense acoustic barrier!
Attenuation from foliage does start to have an effect when its about 100m thick – usually impractical as a noise control measure on most new development sites!
Sorry folks - that’s that myth busted!
However, foliage does have other positive acoustic effects…..
• Firstly, trees provide a visual barrier of a noise source, which is enough to convince many people that they are achieving some level of attenuation.
• Secondly, the movement of the tree leaves on a windy day generates sound itself. The sound of trees rustling in the wind is generally considered to be more pleasing to the ear than, say, road traffic noise, so the trees themselves provide something called "masking" – the principle of generating one (usually more pleasant) sound to cover up an unwanted one.
In general, an effective acoustic screen needs to be dense, solid and imperforate, so stick to fences, barriers and bunds where sound reduction is required.
Get in touch with Auricl for practical, effective noise control solutions and we’ll help you see the wood for the trees!
Next time on Soundbites – "It's Complicated": 10 Things That Make Acoustics Confusing!