Question

You are standing in the middle of a large room listening to a cacaphony of sounds. Rank the intensity of the sounds from each source (1=loudest, 2= next loudest, ...) Consider all objects to be right next to you. If two values are within 0.1 dB from each other, consider them to be the same.

1. Two buzzers each producing a sound with intensity level of 50 dB

2. An object emitting a sound with an intensity level of 10dB.

3. An object emitting a sound with an intensity of 1.0×10^-9 W/m².

4. An object emitting a sound with an intensity level of 60 dB.

Answer 1

1.) 2 buzzers each producing a sound with intensity level of 50dB.

2*50 dB = 50+10log2 = 50+3 = 53 dB

2.) An object emitting a sound with an intensity level of 10 dB.

1*10dB = 10 dB

3.) An object emitting a sound with an intensity of 1.0×10-9 W/m^2.

The reference level is 10^-12W/m^2, so this object is 1000 times as intense as the reference. Therefore it has an intensity of 10*log(1000) = 30dB

4.) An object emitting a sound with an intensity level of 60 dB.

1*60dB = 60 dB

Thus the ranking is:

4, 1, 3, 2