SoundActivity: privacy policy

Introduction

Enlyzr ("we", "our", or "us") provides SoundActivity, an Android app with tools that measure, analyse, record and generate sound. This Privacy Policy explains what the app stores, where it keeps it, and what can leave your device.

The policy covers the Android app. SoundActivity can also work together with a second device on your network that lends its microphone, called a node. A node is a device you run yourself; what the app exchanges with it is described under Connected devices (nodes).

Information the app stores

SoundActivity does its work on your device. It has no user accounts and sends nothing to us. What it keeps, it keeps in its own private storage on your device:

• Sound from the microphone: While a measuring tool runs, the app listens through your device's microphone, or through a USB microphone or audio interface you have plugged in. The sound is analysed in memory. It is written to storage only by the functions that are there to record, and only when you use them: for example the Recorder, the Rolling Buffer, Snapshots, Alerts when set to record, session recording, recording in Preprocessing, and voice memos.
• Recordings and logs: The audio files those functions write, the level logs of the logging tools, and recorded sessions. A recorded session holds the sound and pictures of the tool's screen taken every few seconds.
• Measurement results: Saved curves and results, surveys, trends and history. This includes the results of the hearing checks (for example audiograms) and of the voice tools, if you run them.
• Annotations: Notes, photos, voice memos of up to one minute, and pictures of a tool's screen that you attach to a measurement. A photo is taken by your device's camera app or picked from your gallery at your request; the app keeps its own copy.
• What you type in: The operator's name and role, a company name, address, contact line and logo for report headers, project and client names, the name of a place you visited, and other text you enter. All of these are optional.
• Calibration and devices: Calibration values and history, calibration files you import, and a list of the USB audio devices the app has seen, with their name, maker and product numbers and, where the device gives one, its serial number.
• Audio files you open: The app reads the audio files you pick for analysis, and stores the files it makes from them (for example an edited or cleaned-up copy).
• Settings: Your choices in the app, such as language, theme, profile, tool settings and presets.
• Audit log: A list, kept on your device, of changes to calibration and audio settings, of workflows you ran and of exports you made. It is there so that a measurement can be traced later. The app does not delete it by itself.
• Coach model: If you turn on the Coach (see below), the language model file you downloaded.
• Connected devices: For each node you paired with: its name, its ID, its network address and an access token. If your phone has been a node: its node ID, its name and its pairing PIN.

We do not collect email addresses, contacts or location, and the app does not ask for them.

What leaves your device

Nothing is sent to us, and the app has no advertising, analytics or crash-reporting component that could send anything to anybody else. Data leaves your device in the following cases only, and each of them starts with something you do.

Sharing and exporting

Many tools can export what they made: PDF reports, CSV and JSON tables, audio files, calibration records, equaliser filter files, the audit log, the help text. The app writes the file and hands it to Android's share sheet or file picker; you choose the app or place it goes to. From then on it is in the hands of the app or service you chose.

An export can contain what you entered or measured: the operator's name, your company details, project and client names, the make and model of your device and microphone, measurement results, notes and photos. Look at a report before you pass it on.

The Coach's model download

The Coach is an optional function that explains a measurement in plain language. It is off until you turn it on in the settings. It works with a language model that runs on your device, and the model file has to be downloaded once, when you press the download button for a model:

• Gemma 3 1B (about 660 MB) is downloaded from our own web server, from an address under enlyzr.info/llm/. The server sees your device's internet (IP) address when you download it. The server logs the request as it logs every request: the IP address, the time, the file's address and what the downloading software says about itself. The log is kept for about three months; the privacy page of this website describes it.
• Qwen 2.5 1.5B and Phi-4 Mini are downloaded from huggingface.co, a website run by Hugging Face. As with any download, Hugging Face receives your IP address and the usual details of the request, and its own privacy policy applies to that.

The app sends nothing else with the download: no measurement, no sound and no identifier of its own. By default it downloads over Wi-Fi only. After the download the Coach works on your device: the measurement it explains is given to the model inside the app and is not sent anywhere.

Connected devices (nodes)

SoundActivity can use the microphone of another device on your network. That device is called a node: a second phone running SoundActivity with Node Mode switched on, or a Raspberry Pi running the node software. The phone that shows the measurements is called the controller. All of this is optional, and nothing of it runs until you open the node screens.

The connection between controller and node is not encrypted in this version. Whoever can read the traffic on the network can read what is sent, the PIN and the sound included. Use nodes only on a network you trust.

Looking for nodes. While the Node Manager screen is open, the app asks the local network which nodes are there and listens for their announcements.

Pairing with a node. The app connects to the node at the address it found, or at the address you typed in, and sends the PIN shown on the node. The node answers with an access token. The app stores the token with the node's name, ID and address, and uses it to reconnect. From a connected node the app receives measurement values and, when a tool asks for it, the live sound of the node's microphone. From a Raspberry Pi node it can also copy session logs and short recordings of sound events; these copies are kept in the app's private storage.

Node Mode: your phone as a node. When you switch Node Mode on:

• The phone opens its microphone and keeps running in the background, with a permanent "Node Mode" notification, until you stop it.
• It announces itself every few seconds on the network it is connected to: a random node ID, its name (your phone's model name unless you change it), the port it listens on and the app's version. Every device on that network can see the announcement.
• A device that connects is told, before it has given a PIN, the node's ID and name, the app's version, the make and model of your phone, and its calibration value.
• A device that gives the four-digit PIN shown on your screen receives an access token that is valid for 24 hours. With the PIN or the token it can receive sound levels, loudness values and the live sound of your phone's microphone for as long as Node Mode is on. After three wrong PINs from one address, that address has to wait a minute, and longer after each further wrong PIN.
• Controllers connected at the same time are told each other's network addresses.
• If you also turn on the node's status page, which is off by default, every device on the network can open it without a PIN. It shows the node's ID and name, the app's version, how long the node has been running, how many controllers are connected, and its calibration value. It does not show the PIN or any sound.

Nothing that passes between a controller and a node is sent to us.

Android backup

If you have Android backup turned on, the app's data can be part of your device's Google backup and of a transfer to a new device. The app keeps four things out of both: the nodes you paired with and their access tokens, the tokens your phone issued as a node, your phone's node ID and pairing PIN, and the state of the setup wizard. It does not keep the rest out, so settings, saved results, what you typed in and files can be included. How much Android actually backs up is decided by Android.

Permissions

• Microphone: to measure and record sound. Every live tool needs it, as do the tools that play a signal and measure the answer, voice memos, and Node Mode.
• Notifications: for the permanent notification that Android requires while audio tools or Node Mode run in the background, and for the notification the Alerts tool shows when the sound level crosses the limit you set.
• Running in the background and keeping the device awake: so that a measurement, a playback or Node Mode goes on when the screen is off.
• Network access, network state and Wi-Fi state: to download a Coach model, to find and talk to nodes, and to check whether a network or Wi-Fi is available before it does either.
• Wi-Fi multicast: to receive the announcements of nodes on the local network while the Node Manager is open, and to send the announcement when your phone is a node.
• Vibration: for the metronome's beat.
• Motion sensor at a high rate: the Vibration tool reads the device's acceleration sensor at its fastest rate.
• USB devices: when you plug in a USB microphone or audio interface, Android asks whether SoundActivity may use it. The app reads the device's name, its maker and product numbers and its serial number, to recognise the device again and to match a calibration file to it.

The app has no permission for the camera, for your location, for your contacts or for the files on your device. A photo is taken by your camera app, and files are opened and saved through Android's own picker.

Third-party services

SoundActivity does not integrate any advertising, analytics, tracking or crash-reporting service. It has no user accounts and no in-app purchases. The app does not send any information to third parties, with these exceptions, all described above: the download of a Coach model from huggingface.co if you choose one of the two models hosted there, the apps and services you pick when you share a file, and the Android backup if you have it turned on.

Two parts of the app use components made by others that work on your device. The Coach runs its language model with Google's MediaPipe library, which is built into the app. Two of the hearing checks (Word Recognition and Acceptable Noise Level) have their built-in test words and sentences spoken by the text-to-speech engine installed on your device; which engine that is, and how it works, is set in your device's settings.

Children's privacy

SoundActivity is not directed at children. We do not knowingly collect personal information from anyone, including children.

Data deletion

You can remove data inside the app: the Recorder's recordings, annotations, saved measurements, surveys, projects, trends and stored audiograms have their own delete actions; "Remove model" in the Coach settings deletes a downloaded model; "Forget" in the Node Manager removes a paired node and its token.

You can delete everything the app stores on your device by:

• Clearing the app's data through your device's Settings > Apps > SoundActivity > Storage > Clear data
• Uninstalling the application from your device

Either one removes all of it, the audit log included. If Android backup is turned on, the backed-up copy is managed through your device's backup settings. Files you exported or shared, and anything a node or another device received, are no longer in the app's hands and have to be deleted where they are.

Changes to this policy

We may update this Privacy Policy from time to time. Any changes will be reflected in the "Last updated" date at the top of this policy. We encourage you to review this policy periodically.

Contact us

If you have any questions about this Privacy Policy, please contact us at enlyzr@gmail.com.