01. Introduction & Scope

Welcome to DecibelZen (package name: com.decibelzen.soundmeter), an Android application designed to provide real-time ambient sound pressure level (SPL) measurements, decibel metrics (dBA/dBC), and hearing health guidelines aligned with World Health Organization (WHO) standards.

This Privacy Policy explains how DecibelZen handles hardware access and user privacy. We are committed to complete transparency: our core architectural philosophy is Privacy by Design and Zero Data Ingestion. This policy applies to all versions of the DecibelZen application distributed through the Google Play Store.

02. Microphone Access & Audio Processing (RAM-Only)

To function as a decibel sound meter, DecibelZen requires runtime permission to access your device's microphone (android.permission.RECORD_AUDIO). We maintain an uncompromising commitment regarding how this sensor data is handled:

Technical Processing Details:

• Transient In-Memory Buffering: Short PCM sample buffers are read directly from the hardware microphone into volatile random-access memory (RAM).
• Mathematical Amplitude Calculation: The application calculates instantaneous Root Mean Square (RMS) amplitudes and Fast Fourier Transforms (FFT) exclusively to render numeric decibel readouts, peak hold indicators, and waveform visualizations.
• Immediate Memory Overwrite: Audio samples are purged and overwritten continuously every few milliseconds. No voice data, speech recognition, ambient conversations, or acoustic fingerprints are ever recorded, cataloged, reconstructed, or persisted.
• No File Creation: DecibelZen creates zero audio files (e.g., .wav, .mp3, .aac, .pcm) on the device storage, internal cache, or external SD card.

03. Personal Data & Data Safety Declaration

In accordance with Google Play Data Safety policies, we state unequivocally:

DecibelZen operates 100% locally on your device. We do not maintain any servers, databases, or user registration systems.

04. Permissions Used by DecibelZen

The application requests only the strictly necessary runtime permissions required to deliver its core functionality:

• android.permission.RECORD_AUDIO: Required exclusively to access raw sound pressure levels from the device microphone for decibel calculation. As stated, this is strictly RAM-only and never saved.
• android.permission.POST_NOTIFICATIONS (Optional): If enabled by the user on Android 13 (API 33) or higher, this permission allows the application to show an ongoing foreground notification while continuous sound monitoring is actively running. You can revoke this permission at any time in system settings without impacting basic decibel measurement.

DecibelZen does not request permissions for Contacts, Photos, Storage, Camera, Location, Phone State, or SMS.

05. Third-Party Libraries, SDKs & Cookies

• No Analytics SDKs: We do not bundle Google Analytics for Firebase, Flurry, Mixpanel, AppsFlyer, or any other tracking or attribution SDKs.
• No Advertising SDKs: DecibelZen does not display third-party advertisements and contains no ad networks (such as Google AdMob, Unity Ads, or AppLovin).
• No Cookies or Local Storage Tracking: The application does not deploy cookies, web beacons, tracking pixels, or cross-device fingerprinting technologies.

06. Children's Privacy (COPPA & Families Policy)

DecibelZen is a general-audience acoustic utility suitable for users of all ages. Because DecibelZen does not collect, retain, or transmit any personal identifiable information or audio recordings from any user, we fully comply with the Children's Online Privacy Protection Act (COPPA) and the Google Play Families Policy. We do not knowingly solicit or collect data from children under the age of 13 (or under 16 in the European Union).

07. International Privacy Rights

European Economic Area (GDPR) & UK GDPR Compliance:

Under Regulation (EU) 2016/679 (General Data Protection Regulation), individuals have fundamental rights regarding their personal data. Because DecibelZen collects, stores, and processes zero personal data, we do not act as a data controller or data processor, and no personal data transfers outside your device take place. However, you retain full rights to inspect device permissions and revoke microphone access at any time via Android System Settings.

California Consumer Privacy Act (CCPA / CPRA):

Under the CCPA and California Privacy Rights Act (CPRA), California residents have specific statutory rights:

• Right to Opt-Out of Sale / Sharing: DecibelZen does not sell, rent, disclose, or share consumer personal information with any third party for monetary or other valuable consideration.
• Right to Deletion & Access: Since no personal data is collected or retained on servers or storage, there is no consumer data to access, correct, or delete.
• Non-Discrimination: We provide identical acoustic measurement functionality to all users regardless of their privacy preferences.

Brazil General Data Protection Law (LGPD - Lei nº 13.709/2018):

DecibelZen respects the principles of purpose, adequacy, necessity, and security established by the Brazilian LGPD. No personal data is processed or stored.

08. Security & Data Retention

Because DecibelZen operates with a zero-retention architecture, there are no remote databases, cloud repositories, or user files susceptible to data breaches, unauthorized access, or loss. User calibration preferences and threshold settings are stored strictly on your local device via Android Jetpack DataStore / SharedPreferences and never leave your hardware.

09. Changes to This Privacy Policy

We may occasionally update this Privacy Policy to reflect changes in legal requirements, operational standards, or Google Play Developer Program Policies. Any revisions will be published immediately on this webpage with an updated effective date. We encourage you to review this page periodically.

10. Contact Information

If you have any questions, inquiries, or feedback regarding this Privacy Policy, our acoustic processing methods, or permissions handling, please contact our privacy and engineering team: