Question

Sound level B in decibels is defined as

B= 10 log (i/i)
where i = 1 × 10-12 W/m2 . The decibel
scale intensity for busy traffic is 80 dB. Two
people having a loud conversation have a deci-
bel intensity of 70 dB.
What is the approximate combined sound
intensity?
Answer in units of W/m2

Answer 1

The approximate combined sound intensity is
`I_(T)=1.1*10^(-4)W/m^(2)`

Step-by-step explanation:

The decibel scale intensity for busy traffic is 80 dB. so intensity will be

`10log((I_(1))/(I_(0)) )=80`, therefore
`I_(1)=1*10^(8)I_(0)=1*10^(8) * 1*10^(-12)W/m^(2)=1*10^(-4)W/m^(2)`

In the same way for the loud conversation having a decibel intensity of 70 dB.

`10log((I_(2))/(I_(0)) )=70`, therefore
`I_(2)=1*10^(7)I_(0)=1*10^(7) * 1*10^(-12)W/m^(2)=1*10^(-5)W/m^(2)`

Finally we add both of them
`I_(T)=I_(1)+I_(2)=1*10^(-4)W/m^(2)+1*10^(-5)W/m^(2)=1.1*10^(-4)W/m^(2)`, is the approximate combined sound intensity.