AudioContext: createMediaStreamTrackSource() メソッド

createMediaStreamTrackSource(track)

navigator.mediaDevices
  .getUserMedia({ audio: true, video: false })
  .then((stream) => {
    audio.srcObject = stream;
    audio.onloadedmetadata = (e) => {
      audio.play();
      audio.muted = true;
    };
    const audioCtx = new AudioContext();
    const audioTracks = stream.getAudioTracks();
    const source = audioCtx.createMediaStreamTrackSource(audioTracks[0]);
    const biquadFilter = audioCtx.createBiquadFilter();
    biquadFilter.type = "lowshelf";
    biquadFilter.frequency.value = 3000;
    biquadFilter.gain.value = 20;
    source.connect(biquadFilter);
    biquadFilter.connect(audioCtx.destination);
  })
  .catch((err) => {
    // getUserMedia() のエラーを処理する
  });