how to separate two voices on a recording

I recorded my voice over another singer’s recording using a karaoke machine mike. I now want to be able to increase the volume on my voice and lower the volume of the original singer.
I couldn’t figure it out on Wavepad and Mixpad on NCH software so I downloaded Audacity. I can’t figure it out even though I have searched the forum and Youtube.
Thanks!

I now want to be able to increase the volume on my voice and lower the volume of the original singer.

Keep searching. Audacity can’t split a mixed performance into individual voices.

In my opinion, you will be singing this again with better balance. Or better yet, put the backing track into your headphones and the live recording should be only your voice. You can adjust the individual volumes later with any program.

If this fails, then you may have overdubbing set up wrong.

Koz

In the case of audio with first and second voice, if it is not possible to delete the second voice and leave only the main voice, can I decrease the volume of the second voice?

Can’t identify the frequency of the main voice and list only this in the entire audio?

If you are overdubbing, make sure your Audacity microphone is set to an actual microphone or mixer and not a software device or redirection. That’s the most common cause of a new voice mixed with the backing track by accident.

If you like to record Youtube or other music, then that setting is going to be wrong for overdubbing.

Koz

frequency of the main voice

You may be singing a single note, but because of overtones and harmonics, you’re actually singing a basket of different tones—and some of them are common between different voices and instruments.

Before you sing another one, make sure to sing an overdub test first and see that you end with a clean voice track and a clean backing track. Not a mix anywhere.

https://manual.audacityteam.org/man/tutorial_recording_multi_track_overdubs.html

Koz

In my case I need to separate or decrease a voice from an already recorded audio, it was not done by me. it’s possible?

Probably not, but one thing that you can try:

If you pan the audio left / right, does that make the voice that you want to hear better, worse, or no different?

If the answer is “no different”, then no it is not possible to separate.