The first is vocals, a partnered job with the animators, making micro-adjustments in speed if needed for lip flaps, larger adjustments in space between words to fit cadence, and yes, layering the sounds. Sound files in this case is provided by the voice actors.
The second is foley, the sound effects. There's stock sounds, but any even vaguely competent foley artist will wind up making some of their own for particular noises. Draw a chef knife along a hanger to get a sword-drawing noise, hit a warm steak against tile floor to get a swamp monster's thudding steps, and whatnot. Sound files in this case are created by the mixer.
The third is music and ambiance. How loud must it be in the scene? Don't overpower speaking, but don't go unheard. Get louder when nothing is going on. Alter the song itself to better match a mood. Start and finish it, finding segments that "feel good" to start and finish on, to best suit a scene's length.
But you're talking about the vocals specifically... There is some editing to do in vocals. Do you hear any breaths? Those need to be edited out, unless the scene calls for audible breathing. And of course the space between words is shorter or longer as needed to fit the scene. Vocal pops need to be removed, too. And any volume disparity between voices needs equalizing. And noise removal, but competent voice actors will likely record in sound-absorbing studios where noise removal is not an issue: You don't want to echo like you're in a cave if your character isn't in one (and if they are, they better echo the same as every other character, another job of the audio mixer team: Creating uniform environmental alterations to vocal performances).
A good audio mixer will go unnoticed, because the sound effects sound on point, the voices all mesh and match, and the songs play appropriately, so instead, you can comment on the voice actors, musicians, and scene-setting. When they screw up, is when they get noticed: No one says "man, that last episode the bat screech, that wasn't stock audio, they got real bat noises, wow, respect", but they WILL say "what the hell was that walking noise supposed to be? It sounded like dying rubber ducks!" or "Protagonist 1's voice was just a tiny bit echoey... But Protagonist 2's voice wasn't. Is that going to be a plot point or was it just bad mixing?"
Audio has three parts to the job.
The first is vocals, a partnered job with the animators, making micro-adjustments in speed if needed for lip flaps, larger adjustments in space between words to fit cadence, and yes, layering the sounds. Sound files in this case is provided by the voice actors.
The second is foley, the sound effects. There's stock sounds, but any even vaguely competent foley artist will wind up making some of their own for particular noises. Draw a chef knife along a hanger to get a sword-drawing noise, hit a warm steak against tile floor to get a swamp monster's thudding steps, and whatnot. Sound files in this case are created by the mixer.
The third is music and ambiance. How loud must it be in the scene? Don't overpower speaking, but don't go unheard. Get louder when nothing is going on. Alter the song itself to better match a mood. Start and finish it, finding segments that "feel good" to start and finish on, to best suit a scene's length.
But you're talking about the vocals specifically... There is some editing to do in vocals. Do you hear any breaths? Those need to be edited out, unless the scene calls for audible breathing. And of course the space between words is shorter or longer as needed to fit the scene. Vocal pops need to be removed, too. And any volume disparity between voices needs equalizing. And noise removal, but competent voice actors will likely record in sound-absorbing studios where noise removal is not an issue: You don't want to echo like you're in a cave if your character isn't in one (and if they are, they better echo the same as every other character, another job of the audio mixer team: Creating uniform environmental alterations to vocal performances).
A good audio mixer will go unnoticed, because the sound effects sound on point, the voices all mesh and match, and the songs play appropriately, so instead, you can comment on the voice actors, musicians, and scene-setting. When they screw up, is when they get noticed: No one says "man, that last episode the bat screech, that wasn't stock audio, they got real bat noises, wow, respect", but they WILL say "what the hell was that walking noise supposed to be? It sounded like dying rubber ducks!" or "Protagonist 1's voice was just a tiny bit echoey... But Protagonist 2's voice wasn't. Is that going to be a plot point or was it just bad mixing?"