The sound level at 10 m from a single violin is 15 dB. You are seated in a concert hall, listenting to a violin ensemble comprised of 18 violins, all playing at the same intensity. That is, you are 10 m from the ensemble and each violin is producing a sound of 15 dB at your location, 10 m from the violins. The threshold of hearing is 1.0 × 10-12 W/m2. What sound level are you being exposed to?

Question

anonymous · Answer

i know the equation you have to use but im comfused on how you take in the distance. Can you help me out ty

vincent-lyon.fr · Answer

You do not have to take it into account since the noise level is already given at your location.

irishboy123 · Answer

yes, this question is about adding decibels from effectively the same coherent source times 18.  

dBs cannot be added just by doing 18 x 15dB.  you have to reverse back into intensities, add those up, and then calc a new decibel level

that is what the question is about.