У вашего броузера проблема в совместимости с HTML5
Electrocardiography(ECG, EKG) monitor is the process of recording the electrical activity of the heart over a period of time using electrodes placed on the skin.
This is a 555 timer electronic circuit you can use to make Hospital Drama.
Changing the 150kΩ resistor in this circuit can adjust the interval of the heartbeat sound.