I can understand your concerns. The first step should probably be to test his IQ. Expressive speech/language disorder can occur in a child with normal intelligence. However, it is often present with varying degree of mental retardation and or autism spectrum disorder or attention deficit hyperactivity disorder. Hence, a complete evaluation of this is necessary. While noise making could be an attention seeking activity, it may also be a part of attention deficit hyperactivity disorder. Please discuss with your son’s doctor. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.