A leak in your stethoscope could make an ejection sound & systolic murmur of Mild Aortic Stenosis sound normal. An instrument failure my cause you to misdiagnosis. That's why it's important to regularly test your stethoscope.

3.  Test the stethoscope tubing to swivel stem

Gently blow completely around the stethoscope tubing to swivel stem connection. If you detect a leak you can try sliding the hose off and applying sealant.

IS YOUr STETHOSCOPE working as designed?

TesT your Stethoscope

5. Test the diaphragm ring

Gently blow completely around the diaphragm. You will hear some sounds because of the diaphragm’s natural resonance. If you detect a leak:

  • Tighten ring holding diaphragm.
  • Buy new diaphragm.

2.  Test the stethoscope tubing to metal tubes

Gently blow completely around the interface of metal to stethoscope tubing connection. If you detect a leak you can try pushing stethoscope tubing down on the stethoscope tubing and applying some sealant around the metal tube and then pulling the stethoscope tubing back into place.

Mild Aortic Stenosis

Turn your stethoscope to the bell position and put it on. Be sure the ear tips fit securely in your ear canals. Very gently blow through the tubing into the hole of the bell as pictured. This gives you the experience of what a significant energy leak will sound like. Now blow across the back of your hand for another experience of a slight leak.


We will use this method to check for areas that typically wear out on stethoscopes. As you move around the stethoscope listen for the sound of air blowing over a joint. Turn the swivel to the diaphragm position for the remaining test.

1. Test the ear tips to ear canal


Check the seal around your ears. If you detect a leak try the following:

  • Tighten ear tips
  • Snuggle the ears tips more tightly into your ear canal
  • Try adjusting the metal so that the ear tips align better to your ear canal
  • Try a different size ear tip

Simple rubber tubing can be used to test your stethoscope. It's not terribly sophisticated but you can quickly tell if your stethoscope is one of the 45% of stethoscopes that underperform due to leaks. 

4.  Test the head to swivel stem

Gently blow completely around the swivel joint. If you detect a leak you may try a bell kit replacement. Some vendors offer repair services.

The below graphic illustrates how a leak makes the ES & SM inaudible. You now hear only the S1 & S2, as a normal heart sound. These leaks can be detected and most of them can be fixed. Our testing indicates that up to 45% of stethoscopes leak. Leaks let in room noise and mask the abnormal sounds. Normal wear and tear will eventual cause a leak. Your stethoscope, even if newly purchased, needs to be tested. We recommend testing your stethoscope every couple of months.