Quality of a musical note depends on

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:

Two identical sounds $S_1$ and $S_2$ reach at a point $P$ in phase. The resultant loudness at point $P$ is $n \, dB$ higher than the loudness of $S_1$. The value of $n$ is

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

Which one of the following statements regarding pitch of sound is '$WRONG$'?

Four sources of sound each of sound level $10\,dB$ are sounded together,the resultant intensity level will be ... $dB$