Question

How to calculate intensity level when only intensity of sound is given?

Answer 1

When you've only been given the value of intensity of sound at a particular point in space , you can apply the following formula for calculating the intensity level (β) in Decibels.

The formula is as follows :-

β = 10 ㏒ I'/I₀

where I' is the intensity at that point due to the sound being produced.

and, I₀ = 10⁻¹² Watt/metre² because this small value is the amount of intensity detected in almost complete pin drop silence.

The derivation of this formula is not very important for you if you're in the +2 grades of high school.

Hope this helps you !

Answer 2

1. Find the ratio of the sound intensity to the threshold intensity.
2. Take the logarithm of the ratio.
3. Multiply the ratio by 10.
4. Divide the decibel level by 10.
5. Use that value as the exponent of the ratio.
6. Use that power of ten to find the intensity in Watts per square meter.