I don't baby talk ~ but I do sing (frequently) personalized songs & I do notice she loves me to pipe up with a little Floyd or Queen, just impromptu ~ her little tail just wags like crazy and the butt shake confirms she definitely has good taste in music. At night when she is on the bed and we belt a little something out she will sing along with when the mood strikes.
I talk to her all the time, she comes to work me so it's just her and me in my office and I converse with her when she is awake.
I talk and sing to ours cats, fish and snails as well