<P> With exhalation, the opposite haemodynamic changes occur: left - sided murmurs generally increase in intensity with exhalation . </P> <P> There are a number of interventions that can be performed that alter the intensity and characteristics of abnormal heart sounds . These interventions can differentiate the different heart sounds to more effectively obtain a diagnosis of the cardiac anomaly that causes the heart sound . </P> <P> Clicks--Heart clicks are short, high - pitched sounds that can be appreciated with modern non-invasive imaging techniques . </P> <P> Rubs--The pericardial friction rub can be heard in pericarditis, an inflammation of the pericardium, the sac surrounding the heart . This is a characteristic scratching, creaking, high - pitched sound emanating from the rubbing of both layers of inflamed pericardium . It is the loudest in systole, but can often be heard at the beginning and at the end of diastole . It is very dependent on body position and breathing, and changes from hour to hour . </P>

Dup is the heart sound associated with the closing of the semilunar valves