KOROTKOFF1 proposed the auscultatory method of indirect blood pressure measurement in 1905. His "first" sound has been accepted as the index of systolic pressure. He also pointed out that "at the disappearance of sounds, the manometric figure... corresponds to the minimal pressure." This observation has provoked heated debate, continuing to the present. Staunch adherents of the "last sound" school are vigorously opposed by antagonists supporting "muffling" as the correct index of indirect diastolic end point. The clinical observation of the sudden change in sounds has been proposed by early investigators 2-7 in the field of indirect blood pressure measurement and defended more recently by Roberts,8 Van Bergen,9 Moss,10 and others. Korotkoff's original observations on the other hand have been upheld by a large number of investigators.11-20 Their opinion probably represents a majority view. In 1951, the committee of the American Heart Association under the chairmanship of Dr. Carl J. Wiggers21