Hi,
Yes. Add an Audio Source to the GameObject of each character that speaks. You'll typically have a Dialogue Actor component on the same GameObject to tie the GameObject to an actor in your dialogue database. (If you don't have a Dialogue Actor component, it tries to match the actor's name with a GameObject in the scene whose name matches the actor.)
Assign your audio mixer channel to the character's Audio Source.
During conversations, you'll typically play through an Audio() or AudioWait() sequencer command. If you're specifying audio for the current node's speaker, you can just specify the audio clip, like:
This is because the second parameter, which is the name of the GameObject to play the audio on, is assumed to be the speaker.
If you need to play audio on a different GameObject, specify it as the second parameter:
Note: These audio clips should be in a Resources folder or asset bundle.
An easy way to set up the AudioWait() command is to drag the audio clip from the Resources folder in the Project view to the node's Sequence field.