Please take the following steps to help resolve this issue.
Close out Doodly then, restart your computer, without plugging/unplugging any of your speakers/mic. Then, open Doodly and try again.
Upon launch Doodly saves the input/output audio devices on your computer so if you unplug or plug an audio device while it's already open, it may not be recognized.
Upon launch Doodly saves the input/output audio devices on your computer so if you unplug or plug an audio device while it's already open, it may not be recognized.