Privacy Policy
Decibel Pro processes sound measurements on your device and saves recordings locally. No account is required. The app has no advertising, analytics SDKs, tracking, or automatic uploads of your measurements or media. We do not collect data from the app.
Scope
This policy describes how Decibel Pro, developed by Zhifei Qiu, handles information in the iPhone app and when you contact support. Apple services and this website's hosting are described separately below.
Information used on your device
| Information | Purpose and storage |
|---|---|
| Microphone audio | Used to estimate sound levels and record measurement sessions. Sound analysis happens on device. Completed sessions save an associated audio recording in the app's local storage for playback. |
| Measurement history | Session times, duration, scene labels, sound-level statistics, trends, and exposure estimates are stored locally so you can review completed measurements. |
| Photos and videos | Created only when you choose to take a photo or record a video. Videos include microphone audio. Captured media with sound-level watermarks is saved to your system photo library. |
| Preferences | Settings such as reference calibration, alerts, and background measurement are stored on your device. |
Accessing microphone, camera, or photo-library data locally does not send that data to us. The app does not perform speech recognition, voice identification, or precise-location collection.
Permissions and background recording
Microphone access is required for measurement and audio recording. Camera and photo-library permissions are optional and are used for media capture and saving. You can change permissions in iOS Settings.
Background Measurement & Recording is enabled by default in the app's settings. It continues a session you actively started when you switch apps or lock the iPhone. You can disable this setting or stop the session. It does not start a measurement on its own; calls and other system interruptions may pause recording.
No analytics, advertising, or tracking
Decibel Pro has no account service, developer-operated cloud synchronization, advertising SDK, or third-party analytics SDK. We do not automatically receive your recordings, measurement history, photos, videos, identifiers, or usage activity from the app. We do not sell app data or track you across other apps and websites.
Sharing and system services
You can explicitly share captured media through the iOS share sheet. The destination app or recipient then handles that copy under its own policies. Sharing is initiated by you and does not send a copy to us unless you select us as the recipient.
Photos and videos in the system photo library may sync through iCloud Photos depending on your Apple settings. Device backups, the App Store, TestFlight, and Apple diagnostics are managed by Apple, independently of the app's lack of developer-operated uploads. See Apple's Privacy Policy.
Retention and deletion
You can delete a measurement in History or choose Delete All Measurement Data in Settings. The app deletes the associated local recordings with those measurements. Deleting the app removes its app-local data under normal iOS behavior.
Photos and videos saved to Photos are separate copies. Delete them in the Photos app, and manage Recently Deleted, iCloud copies, and device backups using Apple's controls. Copies you already shared remain with their recipients. We cannot remotely access or delete files stored on your device.
Support messages
If you email qiuzhifei521@gmail.com, we receive your email address and the information you choose to include, such as your device model, app version, issue description, or attachments. This is information you send separately, not automatic collection by the app.
We use these messages to respond to support requests and resolve issues, and retain them only as reasonably needed for that purpose or applicable legal obligations. Please avoid sending private recordings or media unless necessary for your request. You may use the same email address to request deletion of support correspondence.
This website
These product and support pages are hosted on GitHub Pages. The pages do not add analytics or advertising scripts. GitHub may process connection information, such as IP addresses, to operate and protect its hosting service, as described in the GitHub General Privacy Statement.
Children and policy updates
Decibel Pro is a general-audience utility. We do not knowingly collect personal information from children through support correspondence. Contact us if you believe a child has sent personal information that should be removed.
If the app's data handling changes, this policy and the App Store privacy information will be updated. The date above identifies the latest revision.
Contact
For privacy questions or support, contact Zhifei Qiu at qiuzhifei521@gmail.com, or visit Decibel Pro Support.