How to do audio "cancellation"

Hi all.

I have a question regarding audio techniques in Premiere.

I know that when you layer audio, both (or all) tracks play. This is fine in most cases, but in some cases it would help me a lot to have it set up where only the audio on top (or in this case, bottom) plays. Is there a button to press or something that would make it so I don't have to meticulously delete specific sections of audio when I layer on new audio pieces?

Thanks for any help/info on this!