[Greg Blair]

After hours of dealing with the same problem and searching out the web, I tried this and had success! Finally. I encountered this problem with Premiere CS4.

First, quit Adobe Premiere. Next drill down into your project’s “Adobe Premiere Pro Preview Files” (media cache) folder and delete the “.pek” and “.cfa” files in the associated project(s). These seem to get corrupted more often than they should and are frequently the cause of audio that won’t play back. Then restart Premiere. Once you reopen your project, these cache files will automatically be rebuilt. Let Premiere finish this task (shouldn’t take long at all), and then check those clips. About 99.9% of the time, the audio and waveforms will be back.