S1 and S2 are the normal heart sounds you hear when the heart valves close. Heart murmurs are extra sounds that can be heard during systole, diastole, or as a continuous sound. S3 and S4 are abnormal ...

Share on Pinterest Will we soon be able to use an app as an at-home stethoscope? Image credit: Sergey Narevskih/Stocksy. Researchers assessed the feasibility of using a smartphone’s inbuilt microphone ...