Romana’s conversation with herself after Garron steals the tracer from her.
Romana: It’s vital to get it back, what can I do?
K-9: I’ll check my databanks for information.
Romana: I wasn’t asking you K-9.
K-9: No other entity is present.
Romana: I was talking to myself.
K-9: That procedure is illogical. The purpose of speech is to communicate information.
Romana: Be quiet K-9. You’re a very irritating computer.
Note: I don’t think Romana is the only one talking to herself. Only time will tell.