Reagan has quite a low-pitched voice. 

She's alone most of the time and enjoys being like that as any introvert would. However, unlike other introverts, she actually speaks what's really on her mind. She's a woman of few words though. Most of her sentences consist of 4-6 words.

Her voice is a little monotone and sounds emotionless most of the time. 

(Kind of like Raven from Teen Titans for example).