IRCT201412047529N5 IRCT 2014-12-21 Shahed University Vice chancellor for research Effect of nature-based sounds on the level of anxiety and pain Comparison of implementing nature based sounds with placebo on anxiety and pain in patients undergoing cardiac catheterization 2014-08-23 anticipated 130 Complete https://irct.ir/trial/8014 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Used, Assignment: Parallel, Purpose: Supportive, Other design features: The patients are randomly allocated to the experiment and control groups (65 patients per each group). Random allocation to intervention and control groups was done by assigning patients to each group every other week. N/A Diseases of the circulatory system. Intervention 1: The patients in the experiment group will receive the nature- based sounds such as birds’ song, soothing rain sounds, and river stream using an audiotape via fixed earphones. The intervention will be conducted in a quiet room. that will last for 20 minutes, between 25 - 50 decibel (dB) before the cardiac catheterization. The level of anxiety (measured by using spielburger questionnaire) and pain (VAS) hemodynamic parameters (recorded in a checklist) are used before and after intervention, while and after cardiac catheterization. Intervention 2: In the control group received the usual sound environment.