Question

If the intensity level by 15 identical engines in a garage is 100 dB, what is the intensity level generated by each one of these engines?

Answer 1

To develop this problem we will apply the concepts related to Sound Intensity. This can be defined as the power carried by sound waves per unit area in a direction perpendicular to that area. Mathematically it can be written as,

$\Delta L = 10log(n)$

$\Delta L$ = Level Difference

n = Number of equal loud sound sources

n = 15

Therefore replacing we have,

$\Delta L = 10 log (n)\\\Delta L = 10 log (15)\\\Delta L = 10*1.176\\\Delta L = 11.76dB$

Therefore over 100dB the total difference intensity level would be

$L_T = L_0 -\Delta L$

Here,

$L_0 = \text{ Total intensity}$

$\L_T = 100 -11.76$

$_T= 88.24dB$

The intensity level generated by one engine is

$L_T = 88.44dB$