I needed to cache a bullet sound effect, and play it several times "on top of each other". To avoid a GET request on each shot, I cache 5 copies of it and cycle through them on each play()

cacheAudio

sounds = {
    'singleshot': '/assets/sounds/singleshot.mp3'
}

for(var s in sounds) {
    var path = sounds[s];
    sounds[s] = {
        path:path,
        clones:[],
        channel:0,
        play:function(volume) {
            this.channel = this.channel >= this.clones.length-1 ? 0 : this.channel+1
            this.clones[this.channel].volume = volume || 1;
            this.clones[this.channel].play()
        }
    };
    for(var c=0;c<5;c++) { // allow up to 5 shots to be playing at once.
        sounds[s].clones.push(new Audio(path))
    }
}

sounds.singleshot.play(.5) // plays singleshot at half volume
sounds.singleshot.play() // plays singleshot at full volume, "on top" of the previously playing shot