Imagine you’re trying to describe a song to someone, but you can only use words. Now imagine that a patient’s diagnosis depends on the accuracy of your description. This is what auscultation, the process of listening to lung sounds, is like today. Auscultation is the ubiquitous first step in detecting signs of lung pathologies, yet it relies on qualitative descriptors like “moist” and “musical.”

 

The highly subjective process can vary widely between doctors, and for a high-incidence disease like community-acquired pneumonia, auscultation has a positive predictive value of at most 57%, meaning that almost half of the patients who are told that something is wrong are not actually sick.

 

High numbers of false positives lead to significant unnecessary treatment and testing. Preventable, follow-up chest x-rays for pneumonia alone cost hospitals $830 million a year. Many patients are also given prophylactic antibiotics, which add up at an average of $40/course and contribute to the growing problem of antibiotic resistance.