Hear Background

I have a recording on my phone, and I want to only hear the voices in the background? Can anyone help me please?

You can’t “invert” the loudness to make loud parts quiet and quiet parts loud.

Dynamic compression makes loud parts quieter and quiet parts louder, pushing everything toward the same loudness but that doesn’t make the background easier to hear.

Was this an interview? Most software is going to treat the background voices as “noise” and try to get rid of them.

Even worse, phone recorders aren’t really catching the far side voice. They’re recording the echo errors, directional processing, and compression artifacts. So the recording is not going to turn out very well even if you do manage to straighten out the volumes.

If you do this again, set up the phone “Hands-Free” in a quiet room and put it on the table so the bottom of the phone (the microphone) is facing you. Then put the second phone between you and the first phone and record the room.

We should note Audacity can’t be used for law enforcement, conflict resolution, or surveillance. In many places, that’s illegal.

Koz

Again, depending on the goal, Zoom will record the near side and the far side as separate sound files if you ask it nice. But the conversation has to be on Zoom.

The sound quality picks up enormously if everybody is listening on headphones. Zoom doesn’t have to do as much sound processing and it sounds cleaner.

Koz

FFT tools can …
http://mdsp.smartelectronix.com/product/ffttools/ [LEVELS]
DtBlkFx VST plug-in by Darrell Barrell, a free multi effect FFT VST plugin for Windows and Mac [Threshold]
They will generate a lot of digital artefacts, consequently compromising the integrity of what is being said.

You can with “Pop Mute”, though it may not be very useful to do so.
See: Missing features - Audacity Support