How to sound proof a door for a split level house hack?

[Jeff Cua]

Good evening BP! Just curious  if any of you know any good ways to sound proof a common door that enters down to the inlaw/basement where we will be house hacking for a year? We plan to set up a hotel style double door with deadbolts for security but would be nice to have some sound proofing? Do you guys have any input? Thanks!