Tremolo method

tremolo.js

const defaultOptions = {
  speed: 10,
  duration: 1,
  volume: {
    min: 0.1,
    max: 1,
  },
};

tremolo(options = {}) {
  const config = Object.assign(options, defaultOptions);
  const interval = config.duration / config.speed;

  for (let i = 0; i <= config.speed; i++) {
    const newVolume = (i % 2) ? config.volume.min : config.volume.max;

    this.gainNode.gain.exponentialRampToValueAtTime(
      newVolume,
      this.context.currentTime + (interval * i)
    );
  }
}