# Sound Pressure Level

1. Feb 4, 2009

### laheer

Hi, I am new to this forum and i'm not sure if I have selected the correct area to post this question. If you think I should move it then let me know! As you can see, I have worked out part of the question but im stuck when it comes to doing the second half. Any help would be appreciated! Thanks.

1. The problem statement, all variables and given/known data
Assume that your property is situated adjacent to a major road and the occupants are complaining about excessive noise levels. The noise source on the road is 45m away from the rear façade of your property. Measurements made at a distance of 4m from the noise source give an SPL of 85dB.

An acoustic barrier is to be erected between the road and your house. The barrier cannot be situated closer than 4m to either the road or the house and cannot be more than 2.5m high.

Calculate the SPL at the rear façade of your property before the barrier is erected.

Determine the best position for the acoustic barrier and calculate the SPL at the rear façade of you’re property when the barrier is in position.

2. Relevant equations
SPL = a + (b x NR)
or
L2 = L1 - 20. Log r2/r1

3. The attempt at a solution

L2 = 85 - 20. Log 45/4

L2 = 63.98
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution