Okay, that sounds like a fundamentally different issue than you first reported. Please provide more information.
- Type of clips (file type & codec).
- Where they came from (what camera or program).
- How you imported them.
- How long they are and how long you're waiting after importing. Specifically, are you waiting for the audio to be conformed (if the format requires that...)
Also, exact version of PPro ("CC" isn't precise enough); operating system, and other data points requested here that seem potentially relevant: FAQ: What information should I provide when asking a question on this forum?