How Can I Get Certain Calls to Ring Even When My Phone is Silent?

Hey all! I woke up today and missed a bunch of calls because my phone was on silent. Typically, we don't have an on-call service, but that's not the main issue here. I'm looking for a way to set it up so I can receive emergency calls without having to add multiple contacts just to bypass silent mode. Is there a service or product that allows one specific number to ring loud, maybe after a couple of calls? I'm not interested in tracking, just a solution that gets the job done. Any suggestions would be super helpful! Thanks!