nix-conf/modules/audio/default.nix

{ pkgs, ... }:
{
  security.rtkit.enable = true;

  services.pipewire = {
    enable = true;
    systemWide = true;
    alsa = {
      enable = true;
      support32Bit = true;
    };
    pulse.enable = true;
    jack.enable = true;

    wireplumber.enable = true;
  };

  hardware.pulseaudio.enable = false;

  environment.etc = let
    json = pkgs.formats.json {};
  in {
    "pipewire/pipewire.conf.d/91-rnnoise.conf".source = json.generate "91-rnnoise.conf" {
      context.modules = [{
        name = "libpipewire-module-filter-chain";
        args = {
          node.description =  "Noise Canceling source";
          media.name =  "Noise Canceling source";
          filter.graph = {
            nodes = [{
              type = "ladspa";
              name = "rnnoise";
              plugin = "${pkgs.rnnoise-plugin}/lib/ladspa/librnnoise_ladspa.so";
              label = "noise_suppressor_mono";
              control = {
                "VAD Threshold (%)" = 50.0;
                "VAD Grace Period (ms)" = 200;
                "Retroactive VAD Grace (ms)" = 0;
              };
            }];
          };
          capture.props = {
            node.name =  "capture.rnnoise_source";
            node.passive = true;
            audio.rate = 48000;
          };
          playback.props = {
            node.name =  "rnnoise_source";
            media.class = "Audio/Source";
            audio.rate = 48000;
          };
        };
      }];
    };
  };
}