Sound blips — synthesized from nothing

No audio files anywhere on this page. Each sound is an oscillator (a tone generator), a pitch decision, and a fade-out envelope — the audio equivalent of procedural art. Press ▶ Load code, then play the three sounds. Note the pitch randomization: press the same button repeatedly and no two plays match.

// One reusable voice: frequency, how it slides, how long it lives.
function tone({ freq = 440, slideTo = null, type = "square",
                dur = 0.15, vol = 0.2 }) {
  const t0 = ac.currentTime;
  const osc = ac.createOscillator();   // the tone generator
  const gain = ac.createGain();        // the volume knob
  osc.type = type;                     // square = chiptune voice
  osc.frequency.setValueAtTime(freq, t0);
  if (slideTo !== null) {              // pitch slide = laser physics
    osc.frequency.exponentialRampToValueAtTime(slideTo, t0 + dur);
  }
  gain.gain.setValueAtTime(vol, t0);
  gain.gain.exponentialRampToValueAtTime(0.001, t0 + dur); // fade = no click
  osc.connect(gain).connect(ac.destination);
  osc.start(t0);
  osc.stop(t0 + dur);
}

// the one-line trick that makes repeats organic:
function humanize(f) { return f * (0.92 + Math.random() * 0.16); }

sounds.coin = () => {                  // two quick rising notes
  tone({ freq: humanize(988),  dur: 0.08 });
  setTimeout(() => tone({ freq: humanize(1319), dur: 0.18 }), 80);
};

sounds.laser = () => {                 // one steep downward slide
  tone({ freq: humanize(1400), slideTo: 120,
         type: "sawtooth", dur: 0.25, vol: 0.15 });
};

sounds.hit = () => {                   // low, dull, quick
  tone({ freq: humanize(160), slideTo: 55,
         type: "triangle", dur: 0.2, vol: 0.35 });
};

Buttons wake up after you press ▶ Load code. (Browsers only allow sound after a click — that rule is why every web game has a "click to start" screen.)

Coin = two rising notes. Laser = one steep downward pitch slide. Hit = low + dull + fast. Most retro sound design is combinations of exactly these three moves.

Try tweaking: the coin's second note 1319 → 1760 (happier) · laser slideTo 120 → 30 (heavier weapon) · type values — "square", "sawtooth", "triangle", "sine" are four different instruments for free · widen humanize's range (0.92/0.16 → 0.8/0.4) until it sounds drunk, then pull back.

In Godot: the same trio synthesized with AudioStreamGenerator — download sound_blips.gd from the Godot project. In Unity: implement OnAudioFilterRead and fill the sample array — same sine arithmetic. In Unreal: MetaSounds: oscillator → envelope → output, three nodes. Or skip synthesis and use sfxr.me / ChipTone to generate .wav files free. Chapter 07.