Audio that’s been recorded in ‘Stereo’ sound has a left and a right audio channel. If you were to analyze this audio in an audio editing app like Audacity, you’d see the two channels appear as separate waveforms. Most modern devices, whether they’re desktop or mobile ones have a built-in option to switch audio from stereo to mono. This is of course done on the device and it doesn’t change the audio that’s being played. If you want to convert stereo audio to mono audio, you need to edit the audio file and we recommend using Audacity for the job.
Convert stereo audio to mono audio
Open Audacity and add the audio file to it by dragging & dropping it on to the app. If the audio file is indeed in stereo, you will see two different wavelengths, as well as the word ‘Stereo’ written with each wavelength.
Click the dropdown arrow at the top of the wavelength and from the menu, select ‘Split Stereo to Mono’.
When you do that, the track is split into two distinct tracks as shown below. Each track will indicate that it is a mono track. That will do the job. If you want, you can delete one of the tracks here. Go ahead and export the file.
Go to File>Export and select a format to export the audio file to. You will see a prompt telling you that the audio is going to be exported as a mono track. Confirm that you want to export it.
When you add the exported track to Audacity, you will see that there is only one wavelength and that the audio is mono.
If you use Audacity to record audio, and later have to convert the recorded audio from stereo to mono, you can avoid the entire process by just having the app record in mono by default.
To set Audacity to record in Mono, open the app and go to Edit>Preferences. On the Preferences window, select Device and look for the ‘Channels’ dropdown under the Recording section. Open it, and select 1 (Mono). Click Ok, and from this point forward, when you record audio with Audacity, it will be recorded in Mono instead of Stereo. You can change this setting any time however, you won’t be able to convert a mono track to a stereo track the way you were able to convert a stereo track to a mono one. It doesn’t work that way.