I’m trying to overdub my voice to an instrumental track. I’d like to hear my voice in my headphones as well as the existing track I am overdubbing. Is that possible to hear both my voice and my instrumental track in my headphones while recording? Thanks for any advice! Gregg
Yes. I’ve been calling that “perfect” overdubbing, where you hear a theatrical mix of your live voice and the backing track.
There are some restrictions. You can’t listen to the computer. You have to listen to the sound mixer, audio interface, or microphone.
How are you recording the work?
Koz
Thanks for the reply. I’m a middle school chorus teacher, and I made up accompaniment using Finale as an mp3 file. I’m simply dragging the file into Audacity. I want to add my voice as a guide for the kids. I use the CTRL-R to record my voice. When I do that, a new track appears below the mp3 one. I’m using headphones and I have a microphone plugged into my laptop. The other music teacher, who is singing the soprano part, said she could not hear herself sing, which is why I’m dealing with this. Other than this issue, everything else works fine. Great program 
Thanks again for your expertise. Gregg
Hello, Greg.
Listening to your own microphone in real time is not possible, as said, unless you use an audio interface (ex.: Focusrite solo, 2i2 etc.) or at least one dedicated sound card (there are external sound cards to buy). That’s known as latency. Our normal computers, with internal mic or USB mics, can’t process the receive > send back audio in real time, there is a delay (latency).
Other than that, you could achieve listening to yourself + any track in Audacity while recording activating the “Listen to this device” option in Windows (https://winbuzzer.com/2020/08/28/how-to-hear-yourself-on-mic-in-windows-10-via-microphone-playback-xcxwbt). Then, you’d be listening to the mic and could simply overdub in Audacity. That would do, if I understood correctly, but the problem with this, as said, is our computers have latency.
I hope I understood correctly your problem and could explain. 
You can do Simple Overdubbing, where you hear the backing track but not yourself. That’s what she’s doing. She’s only wearing one of her headphone muffs so she can hear herself in her right ear.
She’s part of a multi-city mixdown, but still, she’s overdubbing to a backing track and shipping the whole thing off to Josh (lower left) for editing.
https://www.youtube.com/watch?v=PU8hXDim-1s
Koz
Good idea. Thanks for the reply!