I am impressed how well I hear the heart sounds with the audio adjustment. I have attached the digital attachment to my Littman Cardiology II. I showed a pediatric nurse practioner my new attachment, and she was also impressed. She contacted her husband who ordered her the digital attachment with the stethoscope for her birthday. I need to adjust the app in regards to the EKG recording which appears with alot of distorsion. I may have to call your help line to get more information on how to record a clearer EKG with the app. As a practicing internist, I am impressed and pleased with my purchase. Marie E Schlentz, DO