Good answer.
I just wanted to make sure you were not referring to lots of audio being crammed into a transmitter as high level audio as soooooo many operators do. For some Godforsaken reason a lot of people refer to 1 watt swinging to 50 watts kind of thing as high level modulation.
High level modulation simply means the audio is applied to the final RF stage like plate or collector final modulation. Low level mod is when a low RF level is modulated and the following stages are simply linear amplifiers. I have even heard a lot of folks refer to the crappy audio on AM from a lot of ham rigs as low level modulation simply because it has the ALC knocking the crap out of it. It IS low level mod but not for the reason they think. Again that is just the stickler in me showing. LOL