The site 99% Invisible has an interesting post on the invention of the stethoscope had how it transformed medicine.
René Laennec actually felt that patient’s accounts of their own disease were still important, but the quest for objective information about disease was underway, and the stethoscope was just the beginning. Now we have X-rays, CT scanners and MRI and PET scans. All of these devices are basically trading upon the same paradigm that the stethoscope created: that doctors should be able to detect abnormalities inside the body to reach a diagnosis, regardless of how the patient is feeling.
At the same time, new diagnostic innovations are basically making the stethoscope part of the physician costume rather than a needed diagnostic.
Powerful imaging technologies like ultrasound have made the stethoscope exam less critical to the diagnostic process. Medical students aren’t as good as using stethoscopes as they used to be, and across the board doctors today rely less on the stethoscope to make diagnoses. The rise of portable ultrasound has some doctors arguing that we don’t need the stethoscope anymore… “It’s become almost a ritual more than an actual tool in terms of making diagnosis.”