setBuffer(buf) {
    var numChannels = buf.length;
    var size = buf[0].length;
    var newBuffer = ac.createBuffer(numChannels, size, ac.sampleRate);

    if (!(buf[0] instanceof Float32Array)) {
      buf[0] = new Float32Array(buf[0]);
    }

    for (var channelNum = 0; channelNum < numChannels; channelNum++) {
      var channel = newBuffer.getChannelData(channelNum);
      channel.set(buf[channelNum]);
    }

    this.buffer = newBuffer;
  }
Replace the current Audio Buffer with a new Buffer.

 @method setBuffer
 @for p5.SoundFile
 @param {Array} buf Array of Float32 Array(s). 2 Float32 Arrays
                    will create a stereo source. 1 will create
                    a mono source.