Cache mp3 files in sub folders

How to create page rule to cache mp3 files on sub folders and sub folders trees, example,
I need to cache mp3 files under directory structure like that

/assets/audio/ many sub folders each sub folder has many mp3 files
/assets/sound/sub folders/each sub folder has another sub folders, and all have mp3

will this rule work:

*mydomain.com/*.mp3*
Browser Cache TTL: a year
Cache Level: Cache Everything
Edge Cache TTL: an hour

or do I need to create a page rule for each sub folder which I can not because they are hundreds.

try mydomain.com/*.mp3 instead of mydomain.com/.mp3*