A child was treated for H.influenza menigitis for 6 month. Most important investigation to be done before discharging the patient is -
H. Influenza Type Meninigtis
“It is frequent in children between the ages of 3 and 12 months. Residual auditory deficit is a common complication.”

Since, residual auditory deficit is a common complication of H. influenza meningitis so audiological test to detect the deficit should be performed before discharging any patient suffering from H. influenza meningitis.
In children best test to detect hearing loss is brainstem evoked auditory response.

“Auditory brainstem response is used both as screening test and as a definitive hearing assessment test in children”.
MRI
Brainstem evoked auditory response
Growth screening test
Psychotherapy