Quote:
Originally Posted by Mo_Gearhead
QUOTE: "Here's a tree wall bordering my yard that absorbs sound."
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That borders a street/highway with moving traffic? Or your neighbors yard?
TEST
1. Get a decibel meter.
2. Take readings as cars, trucks, motorcycles pass on the city street.
3. Plant as many trees as you can.
4. Wait 10-?? years for trees to mature.
5. Take decibel reading.
6. Compare step 2 readings to step 5.
I'll await the results.  |
The experimental methodology is flawed - there's no way to ensure that any gains or losses in dB are due to the vegetation. If traffic density doubles in that 10 years, even a positive effect by vegetation would be shown as a loss. Conversely if the vegetation does nothing and the traffic density decreases in 10 years, you'll show a gain.
Objects do diffuse sound waves and absorb some of their kinetic energy.