Since, when you say "I" or "me" your brain is controlling the motor movements associated with the vocalizations, also, to the best of our understanding, the brain is also responsible for conscious thought.  So, since the brain is doing both the thinking and the controlling of the vocalization, I guess the answer would be ... You are your brain,

Your "I" is one aspect of your consciousness, which is part of your mind; your mind is part of the neural processes of your brain; your brain is inextricably integrated with the rest of your body; your body is inextricably integrated with its social, biological, and physical context; this context is part of the universe. So I think the answer to your question would have to be all three of the answers that you have proposed: the mind, the body, and something else, where "something else" may be defined as our context.

There are two formulations of the self that need to be distinguished: the core self and the self image, what Metzinger calls the phenomenal self model (PSM). For more about this see "Two arguments for a pre-reflective core self ....." and "Where Am I? Redux" on my RG page.