one of the basic methods of examining internal organs by listening to the sound phenomena produced in them. Listening to the heart was first introduced in the second century A.D. by the Greek physician Aretes. The French doctor R. Laënnec (1819) developed the modern method of auscultation by employing for this purpose a “medical tube,” or stethoscope. More frequently a phonen-doscope is used for auscultation. This instrument is a hollow capsule with a sound-transmitting diaphragm that is placed against the body of a patient; rubber tubes connect it to the doctor’s ears.

During auscultation of the lungs one listens for the respiratory noises and the different rales that are characteristic of particular diseases. From the variation of the cardiac tones and the occurrence of noises, the condition of cardiac activity and presence of heart diseases can be ascertained. Arteries may be listened to in order to determine changes in the blood pressure. The presence of peristalsis of the stomach or intestines can be established by auscultation of the abdomen, and in pregnancy the heartbeat of the fetus can be detected.

In veterinary science, auscultation is employed in the diagnosis of diseases of the cardiovascular, respiratory, and gastrointestinal systems of animals. In direct auscultation the investigator places his ear against a sheet or a towel covering the portion of an animal’s body being examined; indirect auscultation is carried out by means of a stethoscope or phonendoscope. Instrumental auscultation was first employed in veterinary science by the Hungarian scientist J. Marek in 1901. In the USSR the auscultation method was perfected by the veterinary scientists K. M. Gol’tsman, N. P. Rukhliadev, A. V. Sinev, A. R. Evgrafov, G. V. Domrachev, V. I. Zaitsev, P. S. Ionov, and I. G. Sharabrin.