Sonoline C Fetal Doppler Price in Bangladesh. The Sonoline C baby heartbeat is an advanced model monitor that is equipped with all the modern features. It is available to hear and see the baby's heartbeat through the built-in speakers and LCD screen. Display the baby's heartbeat through a built-in digital heart rate curve screen. It comes with an updated 3-MHz probe that makes it simple to detect the heart rate. It has clinic for daily self check by pregnant woman.