What do the max min values mean in the physical wave form/air pressure?
They describe the maximum positive and negative air pressure that can be measured using that representation and its corresponding digital values.
there is no direct relationship between LOUDNESS and a digitial or analog signal, it is always relative, and depends on frequency ... and amplification.
there is an vague rule, which could give you an idea (but does not make an industry standard math _expression_):
the human ear feels that something is 2 times louder when the amplitude, the pressure, the energy is 4 times higher.
the relationship between 16 bit digital values and GAIN in db/A on the digital layer (i.e. virtually, in a piece of software) is:
log10(sample value/lenght of bitdepth) * 20
thats what you should ue for music software.
i would exlude the 0. from the log() and translate the value 0 directly to -90.0 db/A
for measuring the average rms of a signal a 16 bit resolution would be just fine, so your answer could look something like
(log10(sample value of measured root mean sqare / 65536) * 20 / 2.)
but the whole thing will only be true when the REAL loudness where it is played is somewhere between 0.1 and 140 bd/A ... |