Đúng Chưa?

Tone calibration · Pre-launch

Đúng Chưa? helps you hear, see, and physically adjust your tone shape — one recording, one correction, one retry at a time.

Record your voice

See the tone

Fix the sound

Join the waitlist See the method

Deterministic judgment · Biological coaching · Real-world transfer

The problem

You can know the word and still be misunderstood.

Vietnamese pronunciation is not just vocabulary. Tone height, contour, timing, breath, and mouth position change whether locals understand you — even when your vocabulary is correct.

Textbook knowledge is not sound control.

You can read the tone marks and still produce a shape Vietnamese ears do not recognize.

Polite feedback hides mistakes.

Locals may smile and nod even when they did not understand. You need clearer signal than politeness.

Most apps do not show what your voice actually did.

Flashcards and chatbots rarely show your pitch contour or give one physical correction to retry.

The method

The training loop is simple.

No infinite menus. One phrase, one recording, one correction — until the tone shape is clearer.

Hear the native target.

Listen to the tone shape you are aiming for.

Record your voice.

One clear take. No stacking corrections.

See the tone shape.

Compare your contour to the native trace.

Get one physical correction.

Throat, breath, jaw — not abstract grammar.

Repeat until the signal is clearer.

Retry with the same phrase until the shape stabilizes.

Record it. See it. Fix it. Repeat it. Use it outside.

Why this is different

Not another AI language chatbot.

Đúng Chưa? is built for tone shape and voice signal — not vocabulary drills dressed up as conversation.

Generic language apps

Vocabulary lists
Grammar exercises
Flashcards
Chatbot conversation

Pitch contour comparison
Voice trace you can see
Deterministic, signal-based scoring
One physical coaching correction
Real-world transfer loop

The judgment comes from the sound signal. AI is only used to explain the correction in human language — not to guess whether you passed.

Product preview

One correction at a time.

Early builds focus on clarity over dashboards. You always get a single coaching direction — never a wall of numbers.

Match confirmed

Your tone shape matched the native target.

Ready to try the phrase outside or move to the next word.

Correction

Your tone dipped too low.

Lift the end of the syllable — do not push from the throat.

Retry cue

Keep the tone steady, like a relaxed hum.

One physical image. Record again when you are ready.

Real-world transfer

Practice is not the final test. The street is.

The app is designed to help learners move from isolated tone drills to real Vietnamese interactions. Once your tone is stable in practice, the next step is using it outside — ordering coffee, asking directions, saying the word to a real person.

Field feedback may be used carefully in later versions. We do not promise that every stranger will validate you — only that clearer tone shape makes real conversations more likely.

Early access

Be first to test the Vietnamese tone-calibration loop.

We are building in the open with early testers. Join the waitlist to get updates when the calibration loop is ready for wider testing.

You are on the list.

We will reach out when early testing opens. Thank you for helping shape the training deck.

FAQ

Common questions

Is this an AI tutor? +

Not exactly. The app uses signal-based scoring for pronunciation and AI-assisted explanation for coaching. The pass/fail judgment comes from your voice signal, not from a chatbot guessing.

Does it teach vocabulary?

Not first. It focuses on making the words you already know easier to say correctly.

Which Vietnamese accent?

The first version focuses on a controlled practice deck. Central, northern, and southern support can be expanded carefully as baselines grow.

Will it work in noisy places?

The app is being tested for real Vietnamese environments, but early practice works best somewhere reasonably quiet.

Can it replace a teacher?

No. It gives repeatable sound feedback between lessons — not a full curriculum or human relationship.