Sound Meter privacy policy

Effective November 5, 2026

Sound Meter is a free sound level (decibel) meter app for iPhone and Android and a web app at sound.hertzmc.com, made by Jayden Hertz. This page explains what it does with your information.

The microphone

• Sound Meter uses your phone's microphone only to measure how loud it is around you.
• Sound is measured live on your phone, a fraction of a second at a time, and thrown away right after. Sound Meter never records, saves or sends any audio, to us or anyone else.
• It listens only while the app is open on your screen. It stops when you leave the app or tap Pause.

What's saved on your phone

Only your calibration setting (the number of dB you added or took away) is saved on your phone so it's still there next time. Readings, Min, Avg, Max and the graph are not saved. Uninstalling the app deletes everything. The Android app doesn't copy anything to a Google backup.

App updates

When the iPhone or Android app opens, it checks Expo's update service (expo.dev) for small fixes, so they arrive without a full store update. The check sends the app version, the phone's platform, a random ID made for your install and, like any internet request, your IP address. It never includes any sound. See Expo's privacy policy.

Ads in the iPhone and Android apps

• The apps show one banner ad from Google AdMob. To show and measure ads and to prevent fraud, Google's software in the app collects some information from your device, such as its IP address (which gives a rough location, like your city), device and app details, an advertising identifier, and how you interact with ads. It never gets any sound from the microphone. See how Google uses information from apps that use its services and Google's privacy policy.
• iPhone: the app asks Google for non-personalized ads only and never asks to track you.
• Android: ads may be personalized. You can reset or delete your advertising ID in your phone's Settings (Privacy → Ads, or Google → Ads).
• Where the law requires it (for example in the European Economic Area, the UK and Switzerland), the app asks for your choices before showing ads. You can change them any time in the app: tap i, then Ad privacy choices.
• The web app at sound.hertzmc.com has no ads.

The website

sound.hertzmc.com is delivered by Cloudflare, which counts page visits without cookies (Cloudflare Web Analytics). The sound meter page measures sound in your browser and sends no audio anywhere.

What Sound Meter doesn't do

No accounts or sign-up. No access to your contacts, photos, camera or location. We don't collect any personal information ourselves, and we don't sell your information.

Who else gets data

Only Google (for the ad) and Expo (for the update check) get the data described above. We use them because their privacy commitments protect your data at least as well as this policy does.

Keeping and deleting data

• We keep nothing about you on our own servers, so there's nothing on our side to delete.
• The calibration setting stays on your phone until you change it or uninstall the app.
• Google and Expo keep their data for as long as their own policies say (linked above). You can manage Google's ad data with the links above and, where it applies, Ad privacy choices in the app.
• To ask what data exists or to ask for anything to be deleted, email soundmeter@hertzmc.com. We'll answer and help you with Google or Expo if needed.

Children

Sound Meter is not directed at children under 13, and we don't knowingly collect information from them.

Changes

If this policy changes, we'll update this page and the date at the top.

Contact

Questions? Email soundmeter@hertzmc.com.