A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of

Options

(a) 100
(b) 1000
(c) 10000
(d) 10

Correct Answer:

100

Explanation:

L₁ = 10 log (I₁ / I₀) ; L₂ = 10 log (I₂ / I₀)
L₁ – L₂ = 10 log (I₁ / I₀) – 10 log (I₂ / I₀)
Δ L = 10 log (I₁ / I₂)
20 dB = 10 log (I₁ / I₂)
10 ² = (I₁ / I₂)
I₂ = I₁ / 100.