If you have finished video where you’ve applied edits, you can extract the audio as a whole with a few simple clicks. Use the Extract Audio feature to extract audio from video clips and generate new audio master clips in a project. This preserves the original audio of the master clips. Any source channel mappings, gain, speed, duration, and interpret footage adjustments in the original master clips are applied to the new, extracted audio clips.
In the Project panel in Premiere Pro, select one or more clips containing audio. Choose Clip › Audio Options › Extract Audio. Premiere Pro generates new audio files containing the extracted audio and even adds “Extracted” to the end of the filenames.