The musical interval between two tones of frequencies $320 \ Hz$ and $240 \ Hz$ is

$A$ source of sound emits $200\pi \text{ W}$ power which is uniformly distributed over a sphere of $10 \text{ m}$ radius. What is the loudness of sound on the surface of the sphere?

If the threshold of hearing is assumed to be the reference $(0 \ dB)$,then the threshold of pain is taken to be $120 \ dB$. Let the corresponding sound intensities be $I_0$ and $I$ respectively. Then $\frac{I_0}{I}$ is:

The loudness and pitch of a sound depend on

$A$ hearing test is conducted on an aged person. It is found that her threshold of hearing is $20 \, dB$ at $1 \, kHz$ and it rises linearly with frequency to $60 \, dB$ at $9 \, kHz$. The minimum intensity of sound that the person can hear at $5 \, kHz$ is

How many times more intense is a $60 \ dB$ sound than a $30 \ dB$ sound?