Inclusion Criteria:  ASA I-II patients who are candidate for elective extra cranial surgery. Male and female patients with age between 20-60 years  Exclusion Criteria:  Patients with a conductive or sensorineural hearing loss Patients with a history of ear infection Patients with a history of ear trauma Patients using ototoxic or neurotoxic drugs Patients with sternocleidomastoid muscle pathology (traumatic injury or weakness) that interfere with audiological assessment Patient subjected to gross hemodynamic or ventilatory fluctuations during the operation Patient who developed postoperative shock or major bleeding Patient with a history of neurodegenerative disease, concomitant medical or metabolic illness known to affect cognition Allergy to any drug used in the study. Pregnancy.