Audit Procedures used on SQL Sever DB

I've inherited a DB recently which contains thousands of procs and functions, however most of them are deprecated and no longer in use. I've started adding a piece of code to the procs one at time to notify me if they run, but this process is really quite manual. Is there any way to start an audit, and see which procs run in the next month or two without adding a piece of code to each proc manually?

Thanks, Eric