The heart is talkative, murmuring joyfully, anxiously, enthusiastically, calmly, cheerfully, breathlessly, contentedly, or unhappily. It is not always easy to understand the language of the heart, but applying a stethoscope to the chest is undoubtedly exciting.

This app is designed to describe the pleasure of communicating with the heart; 150 phonocardiograms (PCGs) were selected from more than 5,000 recordings: Each PCG is shown with sound, and 50 PCGs have both sound and echocardiography. The history of the stethoscope and trivia for cardiac auscultation are also included.

It would be great if this app motivates people to learn about cardiac auscultation. I am grateful for all of the support I have received during the recording and interpretation of the PCGs at Matsushita Memorial Hospital. I welcome your comments, questions, critiques, feedback, corrections, stories, experiences, and anecdotes.