Comments on: Noise

By: Tom Simpson

Tom Simpson — Fri, 01 Mar 2013 00:47:06 +0000

And you were right, my house does sit up high (good for views but bad for noise), yet, my next door neighbors on both sides, who sit lower, arn’t as noisy.

By: Tom Simpson

Tom Simpson — Fri, 01 Mar 2013 00:41:04 +0000

Hey guys,
Thanks for the info. Mike, any suggestions? Would soundproof flooring help? Seems like lower frequencies like harleys, logging trucks, and after market exhausts are coming through floors. How do you feel about soundproof drywall? The new windows didn’t help at all and they were andersons. Very expensive. -Tom

By: billzz

billzz — Thu, 28 Feb 2013 22:34:49 +0000

I agree with Mike and may have been too condensed in my writing. Concrete walls do not absorb, but reflect, and if the opposite direction is a hill, like around Placervile or Westlake Village, then the sound waves go up and are heard (as opposed to a flat situation where the sound waves still go up but are not heard. I think the attenuation of vegetation was limited by the area that it took. Also walls that are angled back are better, but more costly. Anyway, it seems to be a solvable situation, except for the amount of money that it takes. They should call Mike!

By: Mike

Mike — Thu, 28 Feb 2013 18:43:22 +0000

@billzz: I’m not sure where you got your information from, but it’s not entirely accurate.Sound (waves) are effected by a variety of physical & environmental elements: The lower the frequency, the further the sounds waves will travel (lower=more base). Altitude, Temperature, & Humidity effects the travel distance (sound travels furthest @ sea level, in warm/humid conditions). As for the “physical” aspects: Solid (Concrete) walls do not technically “stop” sound, they reflect it…. (the waves bounce off solid objects). The amplitude (volume) changes which each bounce/reflection. Trees/bushes do in fact absorb sound waves, more than concrete, but not as much as something much softer: cloth or dirt. Also, the since the leaves are random/scattered, the waves are deflected in different directions, which decreases the amplitude further. (Think of it as throwing a tennis ball against a brick wall, vs a bush, vs an empty tree in winter….. the ball goes different directions at different speed).
When sound hits a freeway wall, it is reflected off of it, usually @ a slight angle, often upward, directing it the opposite direction & slightly upwards, causing it to travel over the opposite wall & up into nearby hills.
I’ve been teaching Sound & Video Production @ the College level for 10+ years & working in the industry for 20+ (including music & radio).

By: billzz

billzz — Thu, 28 Feb 2013 03:43:53 +0000

I did some operations research into this many years ago and it seems that the only thing that will stop freeway sound is a concrete block wall. Bushes and trees have no attenuation, but only divert sound around them. And as has been noted, the concrete walls can magnify sound many miles away. The citizens of Westlake Village (in southern California) had some lawsuits against freeway walls that were miles away from Westlake. The geography (of rising hills against the freeway – just like Placerville) compounds the problem. Consumer’s Report had a good synopsis, but many years ago, so I can’t give a cite.

By: Tom Simpson

Tom Simpson — Wed, 27 Feb 2013 21:02:12 +0000

Mike,
Yes, they have. I’m S/E of Bedford. Should have just tunnelled the highway, I just don’t see any hope for the houses in the area. What a shame.
Tom

By: Mike

Mike — Wed, 27 Feb 2013 19:06:38 +0000

Have they been installing Sound Walls/Concrete Barriers/Walls along the Freeway in the area?

My family noticed the same thing 20+ years ago in the Bay Area (Walnut Creek) actually.
They live about 2-3 miles away from the Freeway, but when they put in “Sound Walls” to minimize the sound for those living next to the Freeway, the sounds simply bounced off the walls (angling toward the hills), where it bounced around & could be heard at the house.. The sounds were 5-10x’s louder after that.
They planted bushes & plants as well, but it took a few years for them to grow & help absorb the sounds.