Am attaching for you Goljan Audio files to this post.
These are MP3 files, in low-quality so that to get smaller sizes for easier download, download one of them and see if you like it to download the others.
Will be uploading more gradually :)
Commonly tested in USMLE when you will be presented with an audio file that sounds like the attached MP3 file below.
This is pleural friction rub and the causes are;
Previous thoracic surgery