The sounds heard over the cardiac region produced by the functioning of the heart. There are four distinct sounds: the first occurs at the beginning of SYSTOLE and is heard as a "lubb" sound; the second is produced by the closing of the AORTIC VALVE and PULMONARY VALVE and is heard as a "dupp" sound; the third is produced by vibrations of the ventricular walls when suddenly distended by the rush of blood from the HEART ATRIA; and the fourth is produced by atrial contraction and ventricular filling
Sound -- Dictionaries : Sonic experience : a guide to everyday sounds / edited by Jean-François Augoyard and Henry Torgue ; translated by Andrea McCartney and David Paquette
Here are entered works on all types of media used for the recording of sound including cylinders, analog discs, digital discs, films, tapes, and wires, as well as works about analog discs alone
Here are entered works describing or recording actual sounds. Works on the use of sounds and of reproductions and simulations of sounds on radio, stage, etc. are entered under subject with subdivision Sound effects, e.g. Radio broadcasting--Sound effects; Theaters--Sound effects --subdivision Sounds under organs and regions of the body and individual wars, e.g. World War, 1939-1945--Sounds
