Notes about the PEK file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The PEK file type is primarily associated with 'Premiere' by Adobe Systems Incorporated. Whenever you open or import a file (movie clip), Premiere automatically converts the audio track into a new proprietary format called conformed audio files. These files are stored in a folder called Conformed Audio Files on the same directory level as the project. Inside the folder are two files for each clip. One has the extension .CPA. This file is the actual newly created audio file. The other file, which has a .PEK extension, contains the graphic waveform data for the audio file.