impulseResponse

impulseResponse.js

// var audioContext = new AudioContext();

function impulseResponse( duration, decay, reverse ) {
    var sampleRate = audioContext.sampleRate;
    var length = sampleRate * duration;
    var impulse = audioContext.createBuffer(2, length, sampleRate);
    var impulseL = impulse.getChannelData(0);
    var impulseR = impulse.getChannelData(1);

    if (!decay)
        decay = 2.0;
    for (var i = 0; i < length; i++){
      var n = reverse ? length - i : i;
      impulseL[i] = (Math.random() * 2 - 1) * Math.pow(1 - n / length, decay);
      impulseR[i] = (Math.random() * 2 - 1) * Math.pow(1 - n / length, decay);
    }
    return impulse;
}