Final answer:
The child may be experiencing mental health issues and should seek professional help from a mental health provider.
Step-by-step explanation:
The symptoms described in the question suggest that the 9-year-old child may be experiencing mental health issues. The child's increased irritability, aggression, and decline in grades, along with the presence of auditory hallucinations (AH) of a voice telling him he is bad, indicate the possibility of a psychiatric disorder. It is important for the child's parents or caretakers to seek professional help from a mental health provider to assess and diagnose the child's condition.