Setting and subjects This study was carried out in the Akbar Abadi teaching center affiliated to Tehran University of Medical Sciences (TUMS).Subjects aged 20—40 years with singleton-term pregnancy,and at least one record of previous C-section delivery were selected. None of the women had; infection problems during pregnancy, preoperative pain, use of sedatives or analgesic medicines, or a history of fetal death. Moreover, they had no history of; auditory deficits, somatic or psychiatric disorders