hi, thanks for asking from HCM. I can understand your concern. The smell loss after head injury could be due to : Olfactory nerve or tract damage in nose or below frontal lobe. It occurs with skull base fracture involving anterior cranial fossa. Usually it is associated with nasal bleed/CSF (brain fluid) leak from nose at the time or after the injury. If it is so, I am afraid that his loss of smell is permanent. Also rule out any nose disease by consulting ENT specialist. He will evaluate him for rhinitis/polyp/mass in nose and degree of loss of smell. If it is not due to nerve injury, recovery is possible. Regarding nerve injury, at present there is no definitive treatment available at present. Coming to your 2nd complaint of sudden hearing of sounds without actual sound is suggesting auditory hallucination . It could be due to temporal lobe damage which might have occurred due to injury. It can be fits also. Kindly consult Neurologist for evaluation. He will do :MRI brain :EEG He will confirm diagnosis. If no lesion, your nephew might need Psychiatrist help for control of hallucination. At home, you can : Ask him to use decongestant if he is allergic :Put fire alarm at house :Ask him not to eat any street food to avoid food poisoning as he will not be able to detect bad food smell. Hope it will help you. Thanks, take care Dr Ishu Bishnoi