Open a book in Wobble today and you'll notice something new. A door in the text creaks. A sword rings. Under a frightening passage, a low, uneasy pad fades in; under a tender one, something warmer. The page hasn't changed. The room has.
why we added sound
Children who struggle to decode often miss the atmospheric cues that fluent readers get for free, the menace in a description, the joke in a sentence, the rising tension before a chapter break. A good audiobook narrator carries those cues with their voice. We wanted Wobble's reader to do the same, without asking children to wait for an audiobook version to exist.
how it actually works
Everything is generated on the device. We don't stream a sound library and we don't call an AI sound API for every page. A small synthesiser inside the app produces the effects, oscillators for the musical ones, shaped noise for the wind, water and footsteps, short envelopes for the bangs and clicks. The music is the same idea: a few slow pads layered into one of six moods (calm, mystery, adventure, tender, magic, scary) and an "auto" mode that picks the mood from the words on the current page.
- No network calls, sound works offline and on school wifi that blocks streaming.
- No per-page cost, you can leave music on all evening without us flinching.
- No giant download, the synth weighs almost nothing compared with a sample library.
- Full parent control, every layer (sfx, music, mood) is a toggle in Settings.
why we didn't use eleven labs for this
We use external AI for the reading voices, where it shines. For sound effects and music we tried it and pulled it back. Generated SFX cost real money per scene, drifted in style between chapters, and stopped working the moment the network blinked. A tiny in-house synth gives us consistency, instant playback and zero ongoing cost. Less impressive in a demo, much better in a Year 3 classroom on a Tuesday afternoon.
where to find it
Settings → Sound. Turn sound effects on, set music to "auto by scene," and let the next chapter score itself. If a child finds it distracting, switch music to off and keep sound effects on, or vice versa. The defaults are deliberately gentle.
We're not trying to turn a book into a film. We're trying to keep a child in the room until the end of the chapter, and a little atmosphere goes a long way.