Skip to main content

Did You Ever Wonder How a Stethoscope Works?

BhavaniBalaravi_practicePageDr. Bhavani Balaravi of Raleigh Cardiology, shared what doctors are listening for when they listen to your chest in the latest edition of   Heart to Heart Magazine, WakeMed Heart Center’s quarterly heart health awareness publication.

“Today’s stethoscopes still play an important role in diagnosing heart, lung and vascular conditions,” said Bhavani Balaravi, MD, FACC, a cardiologist with Raleigh Cardiology – Cary Office.

How does the stethoscope work?

“A stethoscope enhances body sounds and transmits those sounds to our ears,” explained Dr. Balaravi. A typical model has a flat, round chest piece covered by a thin, tightly stretched skin of plastic called a diaphragm. The diaphragm vibrates when sound occurs. These high-frequency sounds travel up the hollow plastic tubing into hollow metal earpieces and to the doctor’s ears.

What sounds does the doctor hear using a stethoscope?

A healthy adult’s heart makes two sounds called a lub (the first part of the heart beat) and a dub (the second part of the heart beat).

“The lub sound is created by near simultaneous closure of the mitral and tricuspid valves located between the atria (upper chambers) and ventricle (lower chambers) of the heart,” explained Dr. Balaravi.

“When the blood leaves the heart via the aorta and pulmonary arteries, the near simultaneous closure of the aortic and pulmonary valves creates the dub sound. When the valves do not completely close, a raspy or blowing noise can occur. This is a heart murmur, an extra sound produced as a result of turbulent blood flow during heart beats, which can mean a valve disorder is present.”

“We also use stethoscopes in conjunction with sphygmomanometers to determine a person’s blood pressure,” said Dr. Balaravi.
Read more about stethoscopes, valve problems, watermelon and much more by clicking here.