Privacy Policy

Effective date: 9 July 2026 · Last updated: 16 November 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.

In brief: Practice records and recordings stay on your device. ZhSound uses no accounts, usage analytics or ads. Apple handles optional voice recognition. If you email support, we receive your email address and what you send.

Download / 下載： 正音 ZhSound on the App Store

1. Data we collect

The App does not track usage, sessions or behaviour. It has no user accounts, analytics backend, advertising or third-party tracking SDKs.

If you choose Settings → Report a problem, the App prepares an editable draft on your device. It can include the app version, device type and operating system, voice settings and recent technical error messages. You can edit or delete any part of the draft. The App never sends the report automatically.

If you send the report using your own email app, Heion receives your sender email address and the contents you choose to send. We use them to investigate and respond to your request. Sending a report is optional. Avoid including passwords or other sensitive information. Your mail provider handles delivery under its own privacy terms.

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.
• Recent technical error entries used to prepare optional support reports. Drafts include entries from the preceding 14 days.

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 microphone access for recording and microphone and speech recognition access for the recognition feature described in Section 3. It can request notification permission when you choose to enable daily reminders. It does not access your camera, contacts, photo library, location, calendar, Reminders app, health data or motion data.

6. Third-party components

The App uses open-source libraries such as pinyin-pro for romanization, OpenCC for script conversion and Dexie for local storage. These libraries run on your device. Optional speech recognition is handled by the provider described in Section 3. Optional support email is handled through your mail app and provider as described in Section 1.

7. Children’s privacy

ZhSound is suitable for general audiences. We do not knowingly collect children’s personal information. If a child needs support, a parent or guardian can contact us. Contact us at support@heiontech.com if you believe a child sent us personal information.

8. Data retention and deletion

Practice data remains on your device. You can clear recordings and reset progress in Settings. Removing the App removes its local data, subject to any backup you control.

We keep support emails for as long as needed to handle your request, maintain necessary support records or meet legal obligations. You can contact us to request deletion of support correspondence.

9. Your rights

To request access to or correction of personal data we hold in support correspondence, email support@heiontech.com. You can also contact us about deletion or how we handle your information.

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: support@heiontech.com
• 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.