stain_docs

Privacy Policy — Stain Acoustics

Effective date: 18 April 2026

Stain Acoustics (“the app”) is an Android application that helps users measure the acoustic properties of rooms and speakers using the device microphone and speakers. This policy explains what data the app touches, where it goes, and what rights you have.

Summary

• No personal data is collected.
• No data leaves your device. The app makes no network requests.
• No third-party analytics, ad, tracking, or crash-reporting SDKs are embedded.
• The microphone is used only while you are actively performing a measurement (e.g. Sound Check, Room Analyser, Simple Sweep, Speaker Analysis, or the Phone Mic Calibration wizard) or viewing the ambient-noise reading on the home screen.

Permissions we request, and why

Permission	Why
RECORD_AUDIO	Required to measure sound pressure level and to record the short log-sine sweep played by the app so we can compute the room/speaker impulse response. Audio samples are processed in memory, written to the app’s private storage only when you choose to export them, and are never transmitted off the device.

No location, contacts, photos, Bluetooth-scan, network, or other sensitive permissions are requested.

Data stored locally on your device

The app stores the following files in its private app-scoped storage (accessible only to the app itself):

• Measurement history (Room analyses, speaker sweeps, speaker profiles) in a local Room database.
• Microphone calibration files (cal_usb_mic.txt, cal_phone_mic.txt) that you upload or generate.
• A user-set phone-microphone sensitivity override value (in the app’s SharedPreferences).
• Any files you explicitly export (WAV impulse responses, FRD frequency responses, JSON metric summaries) — written to the app’s external-files directory on your device.

Uninstalling the app removes all of the above.

Backup

By default the app participates in Android’s system-level “Auto Backup for Apps” feature, which may back the above files up to your personal Google Drive quota. This backup is controlled by your Android settings, not by us, and the data remains under your Google account — we have no access to it.

Children

The app is not directed at children and does not knowingly collect any data that could identify a child.

Changes

If this policy ever changes we will update the effective date above and revise this document. Since the app ships no analytics, the only way you would receive a revised policy is by reading this page.

Contact

Questions or complaints about this policy can be sent to: sales@houseofstain.com