On the homepage, check the option marked in the picture below.
But sometimes the default option maybe altered and we need to switch it back on. MME is the acronym of Multimedia Extensions which is the default audio host for Audacity to make sure sound of any sources on the computer can be input and recorded. If none of the solutions work for you the simplest solution is to install another professional recorder software - FonePaw Screen Recorder (opens new window). Here are how to fix Audacity when it is not recording mic or sound on Winodws. It can be quite irritating if you hear nothing after having spent much time and efforts in recording your fully-prepared singing or some other precious voice. As an open-source app, it possesses powerful editing functions, however, it often doesn't work in terms of recording. Audacity is an open-source and cross-platform audio software which can both record and edit audio. People who love singing and record it or who often need to edit sound track in work may all have heard or used Audacity.