Load your audio into Sonic Analiser and perform a spectral analisys. I recomend Sonic Visualizer as a free/open source tool widely used for audio analisys in research and academia (setting up Sonic Visualizer with the required plugins may be a bit of a project on it self, but there are instructions in the site and it's worth the trouble).

In practical terms I would suggest not to start with Audacity (as excellent tool as it is), but to a more specialized audio analisys tool. Best results (or perhaps, not so bad results) may be achieved if this process is done specifically to different audio segments, depending on how the voices mix along the recording. Then you need to apply filters to remove these frequencies from the audio. It's hard to summarize an approach without going into lengthy technical explanations, and to be honest, I think it will be extremely difficult for someone without the proper training to do it, but even so it may be worthwhile to lay out the basic approach.īasically, you need to identify frequencies in your recording that belong to the voice (ot other sounds) you want to eliminate, but not (as much as possible) to the voices you want to keep. So it's a matter of experimentation and trying to get the best compromise. Depending on the specific case, it may me possible to attenuate the voice you don't want, probably at the expense of the overall quality and perceptibility of the rest. It may or (most probably) may not be possible to do what you wish, as voices are voices and take more or less the same place in the frequency spectrum, so there is no 'magical' way of isolating them. There is no generic recipe to remove a certain specific sound from a recording.

Audacity for phone