by Eric Rackow

Assessing the sounds of the human body was reported in the ancient medical literature. Amongst the earliest known medical manuscripts are the medical papyruses of ancient Egypt dating to the seventeenth century B.C. The Egyptians were one of the first civilizations to systematically document the practice medicine. The first recognized physician was the Egyptian priest Imhotep, who many consider to be the true father of medicine. The Edwin Smith Papyrus (seventeenth century B.C.) and the Georg Ebers Papyrus (sixteenth century B.C.) are an instructional system of the diagnosis and practice of medicine, which referred to audible signs of disease within the body. A millennium later, Soranus of Ephesus identified uterine disease by sound produced when the hand pressed on the abdomen. Egyptian methods of diagnosis used information obtained by examination of the patient. These papyruses contain astute diagnostic observations. For example, hernias were noted "When you judge a swelling on the surface of the belly...what comes out...caused by coughing." The papyruses also included both medical and mechanical means of treatment. Indeed, the Wall of Twin Temple of Kom Ombo on Nile, which was the center for medical care in ancient Egypt, has a hieroglyphic relief depicting various medical and surgical instruments:

Kom Ombo relief


Shown above is the image of the incised relief of the Wall of Temple of Kom Ombo. Many instruments are labeled according to medical use, but some do not have a clear purpose. Could the tube in the lower left corner of the relief between the cupping vessels and shears have been a hearing device used as a stethoscope? (Nunn, J. 1996. Ancient Egyptian Medicine. Norman: University of Oklahoma Press. Page 165)

Hippocrates, the Father of Medicine, advocated for the search of philosophical and practical instruments to improve medicine in 350 B.C. He, in fact, discussed a procedure for shaking a patient by the shoulders (succussion) and listening for sounds evoked by the chest. Hippocrates also used the method of applying the ear directly to the chest and found it useful in order to distinguish between the accumulation of water and pus within the chest. Water bubbled like "simmering vinegar." Caeleus Aurelianus listened to the chest in A.D. 200 by placing his ear in direct contact with it in order to diagnose bronchitis. And Aretaeus of Cappadonia described abdominal sounds in dropsy as being drum like (tympanic).

Despite the return to mysticism in medicine in the Dark Ages, paintings in the Middle Ages depicted physicians examining patients by placing the unaided ear to the chest.

In the sixteenth century, the renown surgeon Ambroise Pare noted that "if there is matter or other humors in the thorax, one can hear a noise like that of a half filled gurgling bottle." The distinguished scientist William Harvey, in his 1616 lecture on the structure and function of the heart, described the heart's motion as "two clacks of a water-bellows to rayse water" and noted that "with each movement of the heart, when there is delivery of a quantity of blood from the veins or arteries, a pulse takes place and can be heard within the chest." And the physiologist Robert Hooke speculated in the 1700s after listening to the beating heart "who knows, I say, but that it may be possible to discover the Motion of the Internal Parts of Bodies....by the sound they make; that one may discover the Works performed in the several offices and shops of a Man's Body, and thereby discover what Instruments or Engine is out of order."

Joseph Leopold Auenbrugger provided the first comprehensive description of percussion of the chest in his 1761 monograph. He began to employ percussion in 1754 as a physician at the Spanish Hospital in Vienna and attributed his discovery to his boyhood experience of watching his father tapping to determine the fluid level in kegs. Auenbrugger tapped the patients with his fingertips with the hand drawn closed to determine the point where percussion detected an abnormality. He described the sounds as either high pitched, muted or dull. The Vienna physician Maximilian Stoll wrote about percussion in 1786 and the French physician M. Roziere de la Chassagne of the Medical Faculty of Montpelier published a French translation of Auenbrugger's work in 1770. But percussion never received general acceptance. It was Jean Nicholas Corvisart, the prominent French physician, physician to Napoleon Bonaparte, and teacher of Laennec, who moved percussion into the mainstream of medical practice. Corvisart adapted Auenbrugger's technique by using the planar surface of his fingers to strike the chest. He published a French translation of Auenbrugger's text in 1808, which was widely read. John Forbes of England translated the text into English in 1824, using original case observations to illustrate the usefulness of percussion. Collin in his 1824 monograph on respiration devoted a chapter to percussion. He preferred slight tapping with a stethoscope as the best means of producing the percussed sound, perhaps reflecting the fact that he was an assistant to Laennec who used this technique. It was A.D. Piorry who introduced in 1826 the use of a solid piece of material, usually ivory, as a pleximeter to improve the quality of sound as a result of tapping the pleximeter placed firmly against the chest ( mediate percussion ) rather than the chest wall itself ( immediate percussion ). He adapted the stethoscope to include a pleximeter and published his inventions in 1828. In Germany, Wintrich introduced the first percussion hammer in 1841. By this time percussion had become an accepted diagnostic modality.

Rene T.H. Laennec's teacher Corvisart was accustomed to placing his ear over the cardiac region of the chest to listen to the heart. Bayle and Double, who like Laennec were students of Corvisart, used the unaided ear to listen to the heart of their patients. Double suggested the regular use of this technique in his treatise on Semiologie published in 1817. Nevertheless, the evolution from listening with the unaided ear ( immediate auscultation ) to the aided ear ( mediate auscultation) awaited Laennec's invention of the stethoscope in 1816. Laennec himself recounts that he recollected the "augmented impression of sound when conveyed through certain solid bodies as when we hear the scratch of a pin at one end of a piece of wood, on applying our ear to the other." Laennec, therefore, "rolled a quire of paper in sort of a cylinder and applied one end of it to the region of the heart and the other end to my ear, and was not a little surprised and pleased to find that I could thereby perceive the action of the heart in a manner much more clear and distinct than I has ever been able to do so by the immediate application of the ear." Laennec continued his study of mediate auscultation with the stethoscope at the Hopital Necker in Paris and published his observations in his classic text on mediate auscultation in 1819. Interestingly, Laennec does not mention in the first edition of his text the experiment of the famous physicist and physician W.H. Wollaston, who in 1810 reported using a long notched stick resting on his foot with his ear resting on the other end to count the sounds of muscle contraction in his foot. Initially, Laennec simply called his invention "le cylindre", but later chose the name stethoscope from the Greek words stethos (chest) and scope (to look at). John Forbes, who translated Laennec's text into English in 1821, first applied the Latin word auscultation (to hear) to the practice of medicine.

Laennec described the different sounds produced in the chest cavity by the movement of air, movement of lung tissue, accumulation of lung fluid, reverberation of the voice and beating of the heart. Mediate auscultation with the stethoscope was accepted slowly into medical practice during the remainder of the nineteenth century. By the twentieth century, inspection, palpation, percussion and auscultation became the standard physical diagnostic approach to examining a patient and remains so today. In the end, the stethoscope became the symbol of the learned physician because it enabled doctors to hear the signs of patients' respiratory and circulatory diseases.

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