With the file extension PEAK so-called PEAK files of the sound processing software Cubase are marked. Peak files contain data for the visual representation of the waveform in the timeline.
PEAK files are automatically generated when importing or recording audio from Cubase. PEAK files do not contain any audio data. For imported audio files, the PEAK file gets the name of the audio file.
PEAK files can be safely deleted, if necessary they are simply generated again by the program. Until Cubase VST the ending ovw was used for this purpose.