Lis has a relatively deep voice. She can raise her voice to a "cute" pitch if she really pushes for it, but it's obviously fake.
Embodying the spirit of a tired and grumpy woman, she tends to sigh and complain under her breath when interacting with the more stubborn students. Her manner of speaking is very blunt and dry, and at times her lack of sleep shows: she doesn't have the most powerful voice, and at times she'll dip into a raspy tone.