Vijay has problems orienting to sounds. for example, he cannot tell which direction music is coming from, either the television or the radio, when he is at home. which area of the central nervous system is most likely malfunctioning to cause this behavior?

I believe the answer is  the midbrain
The midbrain had the function to control both our visual and auditory processing.
A malfunction in this area could make us unable to correctly to process the sound stimulus that came into our auditory nerves, which could lead to the problem that depicted above.