Something that lets me select a frequency above which all sounds would be filtered in real time? I don’t know if a software can separate the high pitched sounds from the rest of the sounds. If it was possible that would be perfect. If not just removing all sounds when any sound goes above the threshold.
Do you mean something like an equalizer? There’s a pulseaudio or pipewire plugin which can do exactly that. You should describe your use case more clearly though.