Question

When a person wears a hearing aid, the sound intensity level increases by 30 dB. The sound intensity increases by

• A. e${}^3$
• B. 10${}^3$
• C. 30
• D. 10${}^2$

Answer 1

The correct option is B 10${}^3$

Let the intensity of the sound without hearing Aid is $I_0$, and the

intensity after wearing hearing aid is $I$, then from the formula,

$L_{db}=10{\log }_{10}\frac{I}{I_0}$

$30=10{\log }_{10}\frac{I}{I_0}$

$\frac{I}{I_0}={10}^3$

$I={10}^3\times I_0$

Option "B" is correct.