A Brief History of the Stethoscope
It is said that French physician René Théophile Hyacinthe Laennec (1781-1826) invented the first stethoscope when presented with an obese lady with an illness. The doctor's modesty prevented him from undressing his patient and her size made it difficult to hear inside her chest. His amateur flute making hobby led him to roll up some tubes and listen to the woman with an apparatus that preserved her dignity.
When we first began our company in the 1970s the H-P stethoscope was still under patent and was selling for less than $50. Recently on Ebay we saw a never used H-P Sprague-Rappaport design stethoscope offered for $2850 (don't worry, shipping was free). The good doctors Sprague and Rappaport tested various aspects in determining what a good stethoscope should be and in the 1950s the H-P company began marketing their stethoscope based on that original data. The design hasn't changed much, the patents have expired. Our Sprague-Rappaport stethoscopes have the interchangeable bells and diaphragms that define that type of stethoscope, as well as 2 discrete tubings, the correct bore and tubing wall thickness. The tubing should be between 12" and 22" and we sell our stethoscopes a little longer than 12" but not so long as to decrease the sound sensitivity.