When a doctor listens to the heart of a person with a heart murmur, they may hear a whooshing, swishing, humming, or rasping sound. This is due to rapid, turbulent blood flow through the heart.

The S3 heart sound occurs as the mitral valve opens and allows blood to fill the left ventricle passively. The sound happens as a result of blood striking the left ventricle during early diastole. An ...