Privacy Policy
Last updated: 12 May 2026 · effective immediately.
Decibel ("the app", "we") is published by Atrium ("the publisher"). This policy explains what we collect, what we do not, and the lawful bases on which we act under GDPR, the California Consumer Privacy Act (CCPA / CPRA), and Apple's App Store Privacy Nutrition Label requirements.
Decibel is built around a single privacy promise: no microphone audio ever leaves your device, and no personal data is collected.
1. What Decibel does with your microphone
Decibel measures the sound-pressure level around you using your iPhone or Apple Watch microphone. The audio buffer is analysed in real time by Apple's Accelerate / vDSP framework and discarded as soon as the analysis is complete (usually within 85 ms).
- Decibel does not use
AVAudioRecorder. - Decibel does not persist raw audio to disk.
- Decibel does not transmit audio to any server.
2. What Decibel stores locally
Decibel uses Apple's on-device SwiftData store to keep:
- The dB-SPL summary of each measurement session you choose to save (LAeq, LAmax, LCpeak, L10/L50/L90, OSHA dose %).
- Per-second LAeq samples from a saved session (used to redraw the in-app chart and the PDF report).
- Saved environment baselines you create ("my living room", "my office").
- Your subscription state (via Apple StoreKit; we never see your Apple ID).
- Your calibration trim and preferences (via
UserDefaults).
This data lives only on your device. It is not synced anywhere by Decibel. If you delete the app or wipe your device, it is gone.
3. Data Decibel does NOT collect
- We do not collect or transmit microphone audio.
- We do not collect your location.
- We do not collect contacts, photos, or HealthKit data unless you explicitly grant permission for Decibel to write environmental noise levels to Apple Health, in which case the data goes to Apple Health and stays under your control.
- We do not use any analytics SDKs (no Firebase, no Mixpanel, no Amplitude, no Crashlytics).
- We do not use any advertising or tracking SDKs.
- We do not request the IDFA (advertising identifier).
4. Network usage
Decibel makes zero network requests during measurement. The only network connections the app makes are:
- StoreKit / App Store, for purchases, restores, and subscription receipt validation (handled by iOS).
- Optional outbound links you tap (Privacy Policy, EULA, Support) — these open in Safari and are not initiated by Decibel.
5. Apple HealthKit
If you grant permission, Decibel can write your environmental noise level to Apple Health using the standard HKQuantityTypeIdentifierEnvironmentalAudioExposure data type. Health data flows through Apple's HealthKit API on your device only; it never reaches the publisher. You may revoke this permission in Settings → Privacy & Security → Health at any time.
6. Subscription billing
Subscriptions are billed by Apple under your Apple ID. You can manage or cancel at any time at Settings → Apple ID → Subscriptions on your device. Decibel does not see your payment details. Apple's App Store privacy practices apply.
7. Children
Decibel is rated 4+ and does not collect any personal information from any user, including children.
8. Your rights
Because we hold no personal data on our servers, GDPR/CCPA subject-access, deletion, portability and "do not sell" requests can be fulfilled by simply deleting the app from your device. Should this ever change, you may contact us at the address below and we will respond within 30 days.
9. Changes to this policy
If we ever change our data practices, we will revise this page and bump the "Last updated" date. Material changes will be surfaced inside the app before they take effect.
10. Contact
Email support@decibel.app.