Party hearing . As the number of people at a party increases, you must raise you
ID: 2241467 • Letter: P
Question
Party hearing. As the number of people at a party increases, you must raise your voice for a listener to hear you against the background noise of the other partygoers. However, once you reach the level of yelling, the only way you can be heard is if you move closer to your listener, into the listener's personal space. Model the situation by replacing you with an isotropic point source of fixed power P and replacing your listener with a point that absorbs part of your sound waves. These points are initially separated by ri. If the background noise increases by ?? = 5 dB, the sound level at your listener must also increase. What separation rf is then required?
Explanation / Answer
You need to shorten the distance to your listener such that the sound intensity level experienced by the listener rises by 6dB. i.e.
Lf - Li = 5 dB
Sound intensity level in dB is defined as:
L = 10 ? log??( I / I?)
(with I sound intensity I?= 10?