In article ,
Michael Bell writes:
|
| That is broadly correct. Trees and vegetation in general don't cut
| down the noise very much. Walls and earthen embankments do.

Actually, they do, but it depends a great deal on the thickness
(obviously) and the frequency. Even a 6' hedge of heavy evergreens
cuts out a LOT of the high-frequency noise. A 2' hedge of beech,
privet or hawthorn may as well not be there.

| Unlike
| light, noise does go round corners, but only weakly so. Most of the
| noise is line-of-sight. Remember that most of the noise is from the
| tyres hitting the tarmac, NOT the engine (just listen to it. What do
| you hear?)[*] so if the line of sight from the road surface to your
| eyes (quite close to your ears) is blocked, then you've done all you
| reasonably can.

The lower the frequency, the more sound 'bends'. That is why you
can do very little about the rumble.

[*] In my case, almost bugger all, but that isn't the point :-)


Regards,
Nick Maclaren.