Dear Kesava sir,
I will try to answer some of the left out questions of Dipil. I am providing the explanation too, so that others can understand the subject, inspite of giving the answers.
Q6. SPL at 200 feet - Ans. 83 dB
Explanation - According to Inverse Square Law, which states that the sound level will drop by a factor of 4 at each doubling distance from the source. It also means that the sound level will drop -20dB at each ten times distance.
(Need your feed back on the same)
Q9. There is a formula for calculation. I was able to recover this from my notes. But I am unable to feed the same formula here as a formula. I hope you can understand & guide us accordingly -
Lc = L1 + 10 Log (10 power ((L2 - L1)/10) + 1
I am unable to evaluate the problem now, as I do not have a scientific calculator now.
Assumption - the answer would be 99 - 100 dB.
Q 11. The classification is Impulsive noise.
Explanation - Impulsive Noise consists of one or more bursts of sound energy, each having a duration less than 1 sec. (They are of two types - explosive generated & impact generated). I think this would be Impact generated of Impulsive noise classification.
Q 12. In addition to Dipil's answer, NRR is the amount of sound reduction that a hearing protection can provide. Higher the NRR dB rating means greater amount of noise reduction.
I am unable to answer the Q 10.
Dear Dipil,
Thank you for the intimation & requesting me to take part in this discussion.
However, I have not gone through the complete discussion, but directly answered the questions from your link. If the answers are already answered, this would be an additional information for all.