You could use the Windows application M²Convert Professional.
There’s a “Split File” feature that lets you launch a player to select one or more portions:
Once in the player, you can play, pause, seek, etc. to get to the start/end point, mark them with the 2 bracket buttons, then click “Add”.
Once you’re done selecting all the needed portions, close the player window and click “Split” in the “Split Media File” window.
I recommend trying the free evaluation before deciding whether to purchase the application.
Note: The portions will be in a video format such as AVI or OGG, but it’s very easy to convert them to MP3 or other Audio formats in one step using the same program’s “Convert Files” feature.
Full disclosure: This application is from a subsidiary owned by the company I work for. It was developed using the LEADTOOLS Multimedia SDK