Here is a recording/playback demo: https://higuma.github.io/web-audio-recorder-js/

All you need to do is:

1. In wiktionary, add a button that will open such screen to each Language/Etymology combination
2. Add an "Upload" button
3. Upload button will upload the sound, and will add a pronunciation record to that word.

IMO, the priority of this feature suggestion should be upped, because it will have a high impact on the quality of wiktionary entries.