function isMediaStreamActive() {
        if (config.checkForInactiveTracks === false) {
            // always return "true"
            return true;
        }

        if ('active' in mediaStream) {
            if (!mediaStream.active) {
                return false;
            }
        } else if ('ended' in mediaStream) { // old hack
            if (mediaStream.ended) {
                return false;
            }
        }
        return true;
    }
Set sample rates such as 8K or 16K. Reference: http://stackoverflow.com/a/28977136/552182
@property {number} desiredSampRate - Desired Bits per sample * 1000
@memberof StereoAudioRecorder
@instance
@example
var recorder = StereoAudioRecorder(mediaStream, {
  desiredSampRate: 16 * 1000 // bits-per-sample * 1000
});