I have only heard back from one school about an interview, but they told me it will only be about 15 minutes. I doubt the school has the time to interview someone for 4 hours, so I am sure they will email you with the specific time slot the week of. I created a google doc with questions I have seen people post about in previous years. I would make sure you prepare an elevator speech about why that specific school (look up their research opportunities, etc), and why SLP, as well as different scenarios. "How would you react if you and a supervisor disagreed over a treatment plan?"
1. Tell me about yourself.
2. Why did you choose our program?
3. What experiences have you had to prepare you for this program?
4. What are specific research interests in communication disorders?
5. If you are accepted to another program, how will you decide between programs?
6. Tell me about a recent volunteer experience.
7. Do you have any questions for me?