Right-Klick Feature at Project-Files to save Audio as Audio-file

I do not have a Audio-Recorder, but the Sound-Quality of the Camera is much better than an other device.
So i record sounds with my camera. But this File is much bigger then Audio only. So i would split it.
If i could add my video-file to the project and say "split sound to file" like the "save frames as picture-sequence"-feature that would be great. Additional options: Use original-stream or MP3, ACC, FLAC ... with Baudrate...