EXPERIMENT · FOR GROWN-UPS

Voice Lab

Find the best voices for Oopsedu's companions. Any button stops whatever is playing and starts right away; the Stop bar at the bottom works at any time. Lines never overlap.

1. Voices on this device

Looking for voices…

Companions (temporary)

Pick any voice for each companion. Choices are saved on this device. If a chosen voice isn't on a device, the companion uses another voice in the same language, then the browser's default.

All voices

English only Likely high quality only

Play	Voice	Language	Runs	Default

Sample for every voice: “Hi! I'm Milo. Want to play a game?” · “Runs: on device” means localService = true; “online” voices need the internet. HQ? marks names that usually mean a higher-quality voice (Natural, Google, Enhanced, Premium, Siri).

2. Speed and pitch

Speed: 1.00× Pitch: +0 (natural) Raising pitch can sound younger. Some voices ignore pitch (Edge “Natural” voices).

Test lines used by “All 5” and the demo:

3. Downloaded voices (Kokoro, Piper)

These voices sound the same on every device but must be downloaded and are slow to make: the first time each line is played it takes a few seconds. They run in the background, so the page stays usable.

Kokoro Open model (Apache-2.0). About 90 MB the first time.

Not loaded

Piper (comparison only) Not for production until its licensing is reviewed. About 60 MB per voice. Needs the online site or a local server.

Not loaded

4. Simon demo

Press “Simon demo” on a companion or a downloaded voice.

Ready when you are.

Sequence: Watch carefully → C → A → T → short pause → Now you try! → your turn.

5. Measurements

Overlap check: nothing played yet

Voice	Line	Make audio (ms)	Audio length (ms)