Answer to Question #2280 in Acoustics for kaitm

Question #2280
A grade-school teacher insists that the the overall sound level in his classroom not exceed 64 dB at his location. There are 25 students in his class. If each student talks at the same intensity level, and they all talk at once, what is the highest sound level at which each one can talk without exceeding the limit? answer in Db(decibels)
1
Expert's answer
2011-04-07T07:37:32-0400
The formula for adding many incoherent sound sources is

<img src="/cgi-bin/mimetex.cgi?L_%7B25%7D%20=%2010%20%5Ccdot%20%5Clog_%7B10%7D%5Cleft%20%28%2025%20%5Ccdot%2010%5E%7BL/10%7D%20%5Cright%20%29%20dB%20=%2064%20%5C%20dB%20%5C%5C%206.4%20=%20%5Clog_%7B10%7D25+%20L/10%20=%201.4%20+%200.1%20L;%20%5C%5C%20L%20=%2050%20%5C%20dB." title="L_{25} = 10 \cdot \log_{10}\left ( 25 \cdot 10^{L/10} \right ) dB = 64 \ dB \\ 6.4 = \log_{10}25+ L/10 = 1.4 + 0.1 L; \\ L = 50 \ dB.">

Answer: The highest sound level should be of 50 dB.

Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!

Comments

No comments. Be the first!

Leave a comment

LATEST TUTORIALS
New on Blog
APPROVED BY CLIENTS