Filmage Editor is a powerful video software. You can extract audio from videos by Filmage Editor.
1. Import the video into Filmage Editor;
2. Drag it into the track;
3. Click the video;
4. Then click Separate Video and Audio ;
5. And the audio will be extracted and placed on the audio track.
You can edit the audio in Filmage Editor or just export it.
If you want to know more about how to edit the audio, please click here.