“A wonderful instrument…is now in complete vogue in Paris…It is quite a fashion, if a person complains of cough, to have recourse to the miraculous tube which however cannot effect a cure but should you unfortunately perceive in the countenance of the doctor that he fancies certain symptoms exist it is very likely that a nervous person might become seriously indisposed and convert the supposition into reality.” —The London Times, September 19, 1824. 
The novel medical instrument described above is the stethoscope. Today, it is difficult for us to imagine that the stethoscope was once briefly judged to be fashionable yet not practical enough to bear any therapeutic influence. Little did the author of The London Times article know, the invention and evolution of the stethoscope would radically revolutionize the way physicians practiced medicine in the 19th century.
In 350 B.C., Hippocrates advocated for a method called “succussion,” which entails shaking a patient by the shoulders and directly listening for the sound in the chest. For thousands of years since then, physicians listened to the internal sounds of the body by pressing one ear against a patient’s body, a method known as immediate auscultation. This was the norm until 1816, when Dr. René Laënnec, a 35-year-old French physician, was consulted to see a “young woman laboring under general symptoms of diseased heart.” Reluctant to press his ear against the patient’s chest, Dr. Laënnec rolled a sheet of paper to create a cylinder. When he pressed one end to the patient’s chest and the other end to his ear, he was delighted by how much more clearly and loudly he heard the heart sound. 
Dr. Laënnec practiced medicine in an era when tuberculosis was a common disease. Interested in studying the sounds of the diseased chest filled with pus, fluid, or cavities, he spent three years improving his instrument to indirectly auscultate, a method he named mediate auscultation. In 1819, he published his design of a hollow wooden tube that was 3.5 cm wide and 30 cm long in his book, “A Treatise on the Diseases of the Chest and on Mediate Auscultation.” At first, Dr. Laënnec was tempted to name his great invention “the cylinder” based on its shape. Thankfully, he settled for the “stethoscope” (“stetho-” for chest, “-scope” for viewing). Dr. Laënnec ultimately died at age 45 of tuberculosis, the very disease he spent most of his life studying. 
Dr. Laënnec’s stethoscope was monaural, which meant that it required only one ear on the instrument. Almost immediately after he published his book in 1819, physicians started attempting to perfect his design by adding earpieces and changing the shape of the bell. In 1843, Charles Williams invented the binaural stethoscope using two bent pipes and lead earpieces. After rubber became commercially available, Phillip Cammann came out with a flexible design in 1851 with a shape similar to the one we know today. His version had ivory earpieces, a wooden chest piece, and a woven tube held together by a rubber band. [4, 5] In the 1960s and 1970s, Dr. David Littman, a Harvard Medical School professor, developed a lighter stethoscope with a tunable diaphragm and better acoustics. 
The stethoscope was embraced soon after its invention in 1816, first in France and then rapidly in the English-speaking world. Over 300 medical students attended Dr. Laënnec’s lectures to learn how to use this novel instrument. In 1826, the first article with directions for using the stethoscope was published in The Lancet. Within a decade, the stethoscope was considered the high-tech gadget in the medical field. Physicians felt their reputations would be in danger if they were seen examining patients without stethoscopes. [7-9] The binaural stethoscope, however, did not become widely popular until the early 1900s due to its higher price, and the fact that its bigger size made it uncomfortable for physicians to carry in their top hats or purses during home visits.  As a result, monaural stethoscopes were still commonly used through the early 1900s, after which improvements in the design and material of the binaural stethoscope made it more convenient to use.
Despite the popularity of the stethoscope, not all doctors were ready to stop pressing their ears against their patients’ chests. In a textbook on auscultation and percussion written in 1890, a Harvard professor in clinical medicine defined the art of auscultation as both immediate and mediate. Although he admitted that the stethoscope provided “aesthetic quality,” better acoustics, and convenience when examining dirty or female patients, he commented that “a good auscultator is not dependent on his stethoscope,” as he urged his students to practice both immediate and mediate auscultation.  Even as late as 1975, an Italian physician felt the need to submit a letter to the editor of Circulation titled, “Immediate auscultation — an old method not to be forgotten.”  The editor quickly rejected the physician’s argument that fine vibration could not be appreciated with a stethoscope and that palpation by hand was not sensitive enough, stating instead that palpation combined with proper patient positioning usually brought out gallops adequately.
Today, the stethoscope remains an indispensable bedside diagnostic instrument that all medical students must possess at the start of their education. New versions of this non-invasive piece of equipment, such as the electronic stethoscope, the recording stethoscope, and even the Doppler stethoscope, are constantly invented and improved. As Dr. Laënnec correctly stated in his will in 1826, the stethoscope is certainly the best part of his legacy.
Dr. Laënnec’s stethoscope. Courtesy of the U.S. National Library of Medicine.
A L’Hopital Necker, Ausculte Un Phtisique (Laënnec, at the Hopital Necker, Examining a Consumptive Patient by Auscultation). Painting by Théobald Chartran (1849-1907). Courtesy of the U.S. National Library of Medicine.
Catalog illustration of stethoscopes, 1869. Courtesy of the U.S. National Library of Medicine.
Medical collectibles, circa 1905. Left, a female obstetrician’s doctor’s bag. Middle and right, an early wooden monaural stethoscope with early painkillers and medications. Courtesy of Antiques Roadshow. URL: http://www.pbs.org/wgbh/roadshow/archive/199705A35.html.
Left, the Cammann stethoscope, mid-19th century. Right, Corwin’s Compound Stethoscope, circa 1896, was a variation of the Cammann stethoscope that allowed two individuals, such as a teacher and student, to listen simultaneously. Courtesy of the National Museum of Health and Medicine.
Dr. Cindy Fang is a resident at NYU Langone Medical Center
Peer Reviewed by Neil Shapiro, Editor-In-Chief, Clinical Correlations
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2. Laënnec RTH. A Treatise on the Diseases of the Chest and on Mediate Auscultation. 3rd ed. London: Gilbert, St. John’s Square; 1829.
3. Roguin A. Rene Theophile Hyacinthe Laënnec (1781-1826): The man behind the stethoscope. Clin Med Res. 2006;4(3):230-235.
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5. Cammann DM. An historical sketch of the stethoscope. Trans Am Climatol Assoc Meet. 1885;2:170-174.
6. Stethoscope. Wikipedia, The Free Encyclopedia. http://en.wikipedia.org/wiki/stethoscope. Updated August 16, 2014. Accessed August 20, 2014.
7. Bishop PJ. Reception of the stethoscope and Laënnec’s book. Thorax. 1981;36(7):487-492.
8. Levin S. The venerable stethoscope. S Afr Med J. 1968;42(10):232-234.
9. Walker HK, Hall WD, Hurst JW, eds. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd ed. Boston, MA: Butterworths; 1990.
10. Shattuck FC. Auscultation and Percussion. 1st ed. Detroit, MI: Davis; 1890.
11. Puddu V. Letter: Immediate auscultation — an old method not to be forgotten. Circulation. 1975;52(3):526-527.