I understood the mathematical meanings of the mean, variance, skewness and kurtosis. But when we calculate these quantities for a signal (say a digital audio signal), what physical meaning do they convey?
I understood mean as the DC component of the signal.
If the mean of the data is made 0, and then if we find the value of variance it is similar to the energy of the signal, the standard deviation is equivalent to the RMS value.
Then what about skewness and kurtosis, what do they physically signify?