Vocal tracks do frequently overlap in character DIALOGUES, makes it hard to hear the main vocal track being worked on. Imagine finte-tuning the visemes of a meeting or group talking scene. Vocal tracks should not be expected to be normalized (have the same loudness/ compression rate) by default - especially when iClone has multiple viseme generating methods each with highly inconsistent loudness outputs. A single global volume control per audio clip type is just insufficient. There should at the very very least be a mute button PER audio clip - voice track or "sound" track. There should also be a volume control PER audio clip. Right click access. With Fade curve options.