Transmission of intracranial pressure (ICP) to the perilymph is performed through cochlear aqueduct and also by other ways. Indirect measurement of perilymphatic pressure may be investigated by observing tympanic membrane (TM) displacement during stapedial reflex contraction, the tympanic membrane displacement (TMD) measurements. This non-invasive technique of examining intracranial pressure (ICP) can be effective in patients suffering abnormal cerebral pathology that could lead in Changes in ICP. It would also be effective in regular monitoring of hydrocephalus patients. This study has a look on this technique which has been reported to provide a reliable, non-invasive measure of ICP.