Privacy Policy

Effective date: 9 July 2026 · Last updated: 9 July 2026

This Privacy Policy explains how the 正音 ZhSound (“ZhSound”, “the App”, “we”, “us”) mobile application handles information when you use it on your iPhone or iPad.

TL;DR — the App collects no personal data. It has no accounts, no analytics, and no ads. Everything runs on your device. The microphone is used only while you are actively recording your own pronunciation, and voice recognition is performed by your device’s own operating system.

Download / 下載: 正音 ZhSound on the App Store

1. Data we collect

None. We do not collect personal information.

• We do not track usage, sessions, or behaviour.
• We do not use analytics, advertising, or third-party tracking SDKs.
• We do not require an account, sign-up, or login.
• We do not ask for your name, email, contacts, or any identifier.

The App has no user accounts and no analytics backend.

2. Data stored on your device

The App stores the following locally, inside the app’s own sandbox:

• Voice recordings you make with the record-and-compare feature.
• Your saved words (收藏), your mistakes notebook (錯題本), and your practice history (used for stats and your daily streak).
• Your settings — display voice, playback speed, tone-display options, Traditional / Simplified script, appearance (light / dark), and daily goal.

This data stays on your device and is removed when you delete the App. You can also clear your recordings and reset your progress at any time from Settings. If you have enabled Apple’s iCloud backup, your app data may be included in your personal iCloud backup, which is governed by Apple’s Privacy Policy, not ours.

The vocabulary, example sentences, and pronunciation clips shown in the App are bundled with the App and load from your device.

3. Microphone and voice recognition

The App uses the microphone only while you actively tap a record button to practise your pronunciation. It is used for two things:

• Record-and-compare: your recording is played back to you so you can compare it with the standard pronunciation. The recording is stored only on your device (see Section 2) and is never uploaded to us.
• Voice recognition (辨識): to check whether your pronunciation is intelligible, the App may pass a short audio snippet to your device’s built-in speech recognition (provided by Apple, or by your browser/Google in the web version). That processing is performed by those providers and is governed by their privacy policies (see Apple / Google). We do not receive or store this audio, and it is not sent to any Heion server.

When you are not recording, the microphone is not active.

4. Pronunciation playback

Standard pronunciation is produced either by your device’s built-in text-to-speech voices or by pre-generated audio clips bundled with the App. These clips are created ahead of time, need no network to play, and never use your voice.

5. System permissions

The App requests the microphone only, and only for the recording and recognition features described in Section 3. It does not access your camera, contacts, photo library, location, calendar, reminders, health data, or motion data.

6. Third-party components

The App is built with common open-source libraries (for example pinyin-pro for romanization, OpenCC for Traditional / Simplified conversion, and Dexie for local storage) that run on your device and do not collect or transmit data. The only off-device processing is the optional voice recognition performed by your device’s operating system, described in Section 3.

7. Children’s privacy

The App is suitable for all ages (rated 4+). Because we collect no data, we do not knowingly collect any data from children.

8. Data retention and deletion

We operate no user database, so there is no personal data to retain or delete. All app data lives on your device; deleting the App deletes it, and you can clear recordings and reset progress from Settings at any time.

9. Your rights

Because we do not collect or process personal data, statutory rights such as access, rectification, deletion, restriction, portability, and objection do not apply here. You retain full control over the locally-stored data on your device.

10. Changes to this policy

We may update this Privacy Policy from time to time. Changes take effect when posted at this URL. The “Last updated” date above will reflect any changes.

11. Contact

If you have any questions about this Privacy Policy, please contact us at:

• Email: [email protected]
• Developer: Heion Technologies
• Jurisdiction: Hong Kong SAR

This policy is provided in English and Traditional Chinese. A Traditional Chinese version is available. In case of conflict between language versions, the English version prevails.