Normalise, Amplitude and Volume difference?

[SonicBreeze]

Normalising, Amplitude modulation and Volume Up/down(effect)- do they affect Audio data diffrently? or they are different names of same process?

often it looks like manipulation of decrease/increase of decibles only.

Question came into mind because I have seen these options available in many audio editors i.e; Soundforge.

[shamann]

Normalize is used to bring audio up to a specific volume level, usually used to make several tracks play together at the same volume. You can usually do it by peak (bring the highest peak in the track up to a specific value) or by RMS (bring the average volume of the track up to a specific level).

Amplitude is the same thing as volume, which in audio waves means the magnitude of its oscillation (as opposed to frequency which is the rate of its oscillation).

Amplitude modulation is the process of altering/varying amplitude. Usually in music it is used to describe effects like tremolo or ring modulation, which are dynamic forms of amplitude modulation, but technically speaking just moving a gain fader could be considered amplitude modulation.

Dynamics processors like compressing, expanding, normalizing and limiting are essentially specialized forms of amplitude modulation, but its rare that people refer to them as such since they are used to alter the dynamics of a signal (bring high and low amplitude values closer together or further apart or to the same level) rather than introduce new information to the signal like tremolo or ringmod. Same applies to AM radio, which modulates the amplitude of a set carrier frequency, and the stuff you hear on the radio is just the modulation of the carrier.

[SonicBreeze]

Thanks for explaining these terms so nicely. Information given surely enriches my knowledge.