Hi,
I have just downloaded Audacity. I am using a USB interface to connect my microphone. My headphone jack is plugged into my laptop. When I record my DAW looks like the attached. Why is only one line of sound wave appearing? Also, in the microphone levels only the L side is appearing, and the headphones sound only comes out on the Left side. It feels like this should be something simple but I cant find out how to fix this. Might it be something to do with the USB interface? PLEASE HELP ME! thank you
If it’s natively a stereo interface (two places to plug in the microphone), the easiest way to stay out of trouble is use the drop-down menu to the left of your track > Split Stereo To Mono.
[X] Delete the dead track.
The one remaining track with your song on it should appear on both left and right headphones.
Any other adjustments need to wait for you to tell is what your interface is.
Koz
hi Koz,
I am not sure what natively stereo means but I only have one mic input (3 pin) on my USB interface, but I did manage to delete the track using the method you suggested. It seems to have fixed the problem too. Thanks so much. Can you explain what you mean about natively stereo? thanks again 
I only have one mic input (3 pin) on my USB interface,
That was a hint for you to tell us what the interface is. If you do that, we may be able to tell you best practices for using it.
Koz
Focusrite makes a bunch of stuff. Focusrite Scarlett Solo?
Koz
Right. So it should be possible to set Audacity to record Mono. That will turn out to be one blue soundwave which will play to both sides of your headphones. It should say Mono on the info panel on the left.
In the sound settings, upper panel next to the microphone symbol, select the interface name and set that for One Channel, Mono or something like that. Macs don’t show you the options not available for your connected devices, so I’m guessing.
Here it is.
The built-in microphone on my machine can be mono and this is what it looks like.
You will need to find the name of your interface. The names get scrambled, so it could be anything. **USB Audio CODEC??**
Koz
This is a good choice for single microphone recording either spoken word or playing a musical instrument. If you buy a higher end stereo interface (two 3-pin XLR connectors), there’s no such thing as simple mono recording. You can’t ever record to the right (bottom channel) and if you force mono, it’s likely to mess with performance volume.
This is the sweet spot.
I have another one. I have a Behringer UM2. They also make a slightly higher-end UMC22.
All “like” being mono. That what I mean by native support for mono.
Koz
This is great. Thank you so much for your help !