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`