complicated question. dont think audiology is like law or business school but it does have some influence over your first job which then has subsequent influence. Remember that most of the hiring world does not really look at US News rankings, but does look at the general reputation of the university. Personally I would take a Northwestern over a Memphis any day (unless I was living in Memphis) irrespective of rankings.
Pitt is a great school and Pittsburgh is a really improving city, but it doesn't have the cache outside of its region as say Ohio State or Indiana (which are ranked below it). Missouri is a completely different experience.
Free vs. student debt is a real challenge and either way you would be ok. More to life than money, but with the expected salary you have to be careful. How much debt do you already have?
Bottom line (flip a coin and then just take a deep breath and jump!