The decibel scale is logarithmic** so to add two sounds you need to 'anti-log' the amounts then re-log the result.
https://en.wikipedia.org/wiki/Decibel
decibel is one tenth of a bel so you need to convert first:
80 db = 8 b
so compute 10*log(10^8 + 10^8)
This comes out as 83 db
** so if the db goes up by +10 the sound is 10 times as loud.
Bob
]]>I have two very loud air conditioners from the two zombies who live next door to me and require air conditioning when the outside temperature is 51 F. I guess they have to keep their skin from rotting off their already ugly faces...
I needed to know the intensity of the noise they were producing. I got it from these two sites
http://www.engineeringtoolbox.com/addin … -d_63.html
https://noisemeters.com/apps/db-calculator.asp
If you use their calculator you will see the book answer is correct.
They appear to be using this formula:
with
]]>(ex) What is the approximate combined loudness in decibels of a garbage disposal truck and a washing machine, each with a sound intensity of 80 decibels?
It looks like a simple problem. I thought the answer was 160 decibels. I got that by multiplying 80 by 2 since the two sounds have the same intensity. But, the answer key says 83 decibels.
Is the answer wrong? Please give me your comments. Thanks.
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