WEBVTT 00:00:03.668 --> 00:00:07.209 Heart sounds that are soft and difficult to hear 00:00:07.209 --> 00:00:08.916 are most common when there is something 00:00:08.916 --> 00:00:11.497 between the heart and the stethoscope. 00:00:11.497 --> 00:00:13.268 Common causes include 00:00:13.268 --> 00:00:16.873 pericardial effusion (fluid surrounding the heart), 00:00:16.873 --> 00:00:21.652 pleural effusion (fluid present in the thoracic cavity around the lungs), 00:00:21.652 --> 00:00:23.572 and obesity.