audioBuffer.ts

const resampling = (audioBuffer: AudioBuffer, targetSampleRate: number): Promise<AudioBuffer> => {
  const offlineAudioContext = new OfflineAudioContext(1, audioBuffer.length, targetSampleRate);

  const source = offlineAudioContext.createBufferSource();
  source.buffer = audioBuffer;

  source.connect(offlineAudioContext.destination);
  source.start();

  return offlineAudioContext.startRendering();
};

const convertBlobToAudioBuffer = async (myBlob: Blob): Promise<AudioBuffer> => {
  const audioContext = new AudioContext();
  const fileReader = new FileReader();

  return new Promise((resolve, reject) => {
    fileReader.onloadend = () => {
      let myArrayBuffer = fileReader.result;

      if (!(myArrayBuffer instanceof ArrayBuffer)) {
        return reject(new Error('Failed to convert Blob to ArrayBuffer'));
      }

      audioContext.decodeAudioData(myArrayBuffer, audioBuffer => {
        resolve(audioBuffer);
      });
    };

    //Load blob
    fileReader.readAsArrayBuffer(myBlob);
  });
};