For speech-language pathologists, AAC specialists and school teams
Oso Voice is written to a published clinical vision and audited against it. This page gives you the stance in your own vocabulary, the facts you need to evaluate it, and the evidence behind each decision. We would rather you read the open questions than take our word for the settled ones.
The clinical stance
Fourteen principles govern the app. These ten shape it most; the full list, with sources and the amendment log, is in the vision document.
Core vocabulary first
A curated set of high-frequency words in fixed positions on Home, in Fitzgerald order (pronouns, verbs, descriptors, social). Fringe vocabulary lives in semantic folders one level deep.
Motor-plan stability as a hard constraint
Within a chosen grid preset no update may relocate a symbol. Vocabulary grows by revealing hidden cells. A preset change is a warned re-baseline event; cross-preset stability is ordinal.
Flat, shallow navigation
Navigation depth costs more accuracy and speed than a larger symbol count on one page. Folders are one level deep, named semantically and concretely, never alphabetically split.
Presume competence
Defaults assume the user can learn the full system. Nothing is gated behind an adult's guess at cognitive level.
Aided language stimulation
Partners can model on the device without unlocking anything. The caregiver check protects Settings only, never the grid.
Communication is never a contingency
Access to the app, to vocabulary or to a specific word is never tied to compliance. A learned word cannot be hidden as a consequence.
Protest and regulation vocabulary is plain speech
no, stop, help, more, again, want, finished, pain and body-state words carry no jump, no confirmation and no special behaviour. A validator blocks any jump target on them.
Colour is a search aid, not decoration
Five-key Modified Fitzgerald colour as a thin border on white cells. Pastel fills are an opt-in for larger grids. Folder chrome is neutral gray on every grid.
Sensory-safe defaults
Gentle Mode, a calibrated low-arousal palette, ships alongside the standard one. It is not a dark mode.
Literal iconography and reading-ease type
One concrete icon family, always with a text label. Lexend throughout, no italics, no all-caps, 16px minimum.
Colour coding
The five-key Modified Fitzgerald scheme partners already know, rendered as a thin border around a white cell. The social key covers social phrases, prepositions, connectors, time words and question words. Full-cell pastel fills are available as a default-off caregiver setting for larger grids, using the literature's own per-category tokens.
The formatting evidence- Pronouns and people
- Verbs
- Describing words
- Nouns
- Social words and prepositions
- Folders are gray. Navigation is never a grammar colour.
Facts for an evaluation
| Platform | iPhone and iPad, one universal app with an adaptive grid. iPad is a first-class target, not a scaled phone. Android is planned for a later phase. |
|---|---|
| Grid presets | Named tiers, not sliders. iPhone: 3 by 3, 3 by 4, 3 by 5. iPad: 4 by 4, 5 by 4, 6 by 5. Defaults are 3 by 4 and 5 by 4. Orientation is part of the motor plan and is held stable. |
| Home composition | Curated core words in Fitzgerald order plus a fixed trio of gray folders (Words, and two curated categories, People and Feelings by default) in the last three cells of the bottom row on every preset. A frozen core-word strip sits above the grid. |
| Smart jumps | Activity verbs (eat, drink, play) may navigate to their category after speaking. Optional, off per word when the setting is off. Protest and regulation vocabulary can never carry a jump; the package validator enforces it. |
| Vocabulary | A curated core and fringe package with semantic folders one level deep. Caregivers can add words, change labels and pronunciation, attach photos, and reveal hidden words. Added words take the next free cell and stay there. Learned words cannot be deleted; they can be hidden by a caregiver, never as a consequence. |
| Speech | On-device Apple voices, including enhanced and premium downloads and Personal Voice where the device supports it. Novelty voices are filtered from the picker. The voice never changes without a caregiver choosing it. A speech failure is never silent. |
| Access methods | Direct touch in v1. Switch scanning and eye gaze are roadmapped for a later phase and are not part of the current baseline. |
| Prediction | None. The grid is static regardless of what was just selected. A contextual next-word strip is an open question in the vision and is not built. |
| Data | Nothing leaves the device. No accounts, analytics, advertising, crash reporting or network use. Usage counts are kept on device for caregivers only. Relevant for school procurement and for families who have been burned before. |
| Pricing | One paid purchase, no subscription, no in-app purchases, no free tier. Nothing inside the app is tied to payment and the app can never stop speaking. |
| Scope | Not a therapy-delivery platform, not an assessment or diagnostic tool, not an engagement product. Daily-active-use and session length are not design targets. |
The evidence, by question
Each piece is the working document, published as written, with the vendor survey, the literature and the decision taken.
Core words on Home, folders at the periphery
Why no word-to-word correlation mechanics in v1
Position stability and grid presets
Grid navigation and position stability: competitive research
Semantic subfolders, no alphabetical splits
Within-category organisation: vendor scan and proposed taxonomy
Folder overflow, pagination, page order
Border accent rather than cell fill
Voice roster, novelty-voice filtering, custom words
Where the app sits in the market
Understanding the AAC landscape: full project research report
Tell us where we are wrong
The vision document lists the open tensions we have not resolved, including the adult register of vocabulary and grid-size configurability. If your clinical experience bears on any of them, or if you want a pre-release build for a client or a classroom, write to us.