gistfile1.js

var playSingleChime = function()
{
    var context = new webkitAudioContext(),
        gain = context.createGainNode(),
        osc = context.createOscillator();

    osc.connect(gain);
    gain.connect(context.destination);

    osc.frequency.value = 1000.0;
    osc.type = osc.SQUARE;

    gain.gain.setValueAtTime(gain.gain.value, context.currentTime);
    gain.gain.linearRampToValueAtTime(0.0, 0.5);

    osc.noteOn(0);
    osc.noteOff(0.5);
}