Express Cue

Overview #

Express Cue turns a description of a sound into a short audio clip. You give it a few words — a bright chime, distant thunder, a soft click — and it gives back a clip of up to a few seconds, along with the settings that produced it so you can adjust and render again. Use it for interface sounds, alerts and placeholder ambience.

Express Cue is a sound-cue generator: it reads a short text description of a sound — “short bright chime, two notes rising”, “low rumble of distant thunder” — and returns a rendered cue of between 0.1 and 6 seconds as 24 kHz mono WAV. It does not generate audio samples directly. The model predicts a kind from a catalogue of eighteen sound kinds and a set of continuous synthesis parameters, and a deterministic synthesis engine turns those parameters into sound.

It is the only member of the Sound family and the one Express model that does not speak. Its one sibling in the series, Express Voice, reads text to be spoken; Express Cue reads text that describes a sound. The two share one style of API surface, one runtime convention and one licensing stance, and differ in what they return.

Because the audio is rendered by a fixed engine from a small set of parameters, every render is reproducible, inspectable and short: the same description and seed give the same bytes, the parameters come back with the audio so a host can adjust and re-render them, and nothing the model returns is a recording.

Intended use #

• Interface cues a host application plays on events: a confirmation chime, an alert, a tick while something loads, a swoosh on a transition.
• Placeholder ambience and textures — rain, wind, static, an engine hum — for a prototype that needs sound before a sound designer does.
• Reproducible sound assets: a description and a seed pinned in configuration render the same cue on every deployment.
• A parameter starting point: a host reads params from one render, edits them and calls the service's direct render route.

Out of scope #

• Speech of any kind — Express Voice speaks; Express Cue never does.
• Music: melodies, chords, rhythm patterns or anything longer than one short cue.
• Sampled or recorded audio: the engine synthesises every sample; there is no sample library.
• Sound design or foley that needs more than one cue of at most six seconds.

Choose Express Cue when #

• The host needs a short, non-verbal sound from a description and wants the result to be reproducible and adjustable.
• The description fits one of the eighteen kinds — tones, chimes, alerts, clicks, transitions, noise textures and a few environmental sounds.
• Otherwise choose Express Voice, the Voice family default for spoken text. Neither series has a music or sound-effects library model.

Specification #

Try it #

You send

The description “short bright chime, two notes rising”.

You get back

A chime under a second long, as a WAV file, plus the settings that made it, so you can tweak and re-render.

The same exchange as the API sees it:

{
  "text": "short bright chime, two notes rising",
  "seed": 7
}

{
  "ok": true,
  "engine": "express-cue",
  "duration_seconds": 0.9,
  "params": {
    "kind": "chime",
    "duration": 0.9,
    "base_freq_log2": 10.2,
    "partials": 4,
    "inharmonicity": 0.02,
    "attack": 0.005,
    "decay": 0.25,
    "sustain": 0.2,
    "release": 0.4,
    "noise_colour": 0.0,
    "lowpass_log": 13.5,
    "filter_sweep": -0.5,
    "am_rate": 0.0,
    "am_depth": 0.0,
    "pitch_glide": 5.0,
    "repeat_count": 2,
    "repeat_interval": 0.18,
    "reverb": 0.15,
    "gain": 0.8,
    "seed": 7
  },
  "wav_base64": "UklGR…"
}

Limits & safety #

Express Cue does not hear anything: it reads a text description, and the engine it drives never sees the description. It does not see who asked, where the cue will play, or anything about the host's audio pipeline.

• It does not produce speech, words or anything with a linguistic meaning; a description that asks for a voice renders as a tone or a noise of some kind.
• It does not produce music: no melody beyond a pitch glide or a short note sequence, no harmony, no rhythm pattern beyond repeats.
• It does not play recordings: every sample is synthesised, so a description of a specific real sound — a named bird, a particular engine — renders as the nearest kind, not the real thing.
• It does not render longer than six seconds or shorter than a tenth of a second; a request for a minute of rain gets six seconds of rain.
• It does not read descriptions outside its template vocabulary reliably; an unfamiliar phrasing lands on the nearest hashed features, and the kind may be wrong.
• It does not control loudness in the host: gain bounds the file's level, but the host decides how loud the cue plays.

Related models #

Latest versions #