I'd quite like to know this myself. I too took the Audacity approach and it's too boring and cumbersome to to lots of files. I don't trust most applications or services since they usually contain adware or install bloatware silently.Is there a way to mass convert files? Audacity does one at a time, i found one converter and it only converts MP3. I have M4As and WMAs. And im trying to convert 90 files, not something i want to do manually 1 at a time.