Last updated October 2, 2026

Privacy and microphone use

The meter needs microphone permission to react to changing sound. Its core measurement runs locally in the browser and is designed not to record or transmit classroom audio.

What happens after you enable the microphone

Your browser asks whether this site may access an audio input. If you allow it, the page receives a live media stream and calculates relative frequency energy with the Web Audio API. The page does not create an audio file, transcribe speech, identify speakers or connect the microphone samples to a server.

How to stop access

Select Stop microphone to stop every track obtained by the page. Closing or leaving the page also stops the tracks. Your browser and operating system display their own microphone-use indicator and retain control over site permission.

Settings stored on the device

The selected meter view, a customized Voice Level Chart and CHAMPS Chart Maker activity drafts may be stored in local browser storage so the next session opens with the teacher's preferred display, class name, labels, examples, print style, display board, character theme, output layout and current level. The current-room match stays in memory only for the active microphone session. These settings contain no audio and can be removed by clearing this site's browser data.

If a teacher chooses Share / embed, the chart settings are encoded in the link fragment after the #. That fragment can be read by the recipient's browser to rebuild the chart, but it is not sent to our server as part of the page request. Anyone who receives the copied link can see the class name and wording included in that chart, so do not place private student information in those fields.

The same action can create iframe code for an ad-free classroom display. The embedded view loads the chart from this site, keeps the setup in the link fragment, requests no microphone permission and includes a route back to the full editor. The website or learning platform where a teacher places that iframe may have its own privacy practices.

Live signal and session summary

The relative signal, session time, in-range percentage and quiet streak are calculated in memory for the open page. They are not student records, are not tied to an account and reset when the session/page is restarted.

Optional feedback and public comments

The tool page may invite a teacher or other adult visitor to choose a result rating and submit a written comment. A display name is optional. The rating, comment, display name, page path and submission time are sent to a Cloudflare Worker and stored in Cloudflare D1 for review. A short-lived Turnstile token is sent to Cloudflare for anti-spam verification but is not published with the comment. Microphone samples and session measurements are never included with feedback.

New comments are not published automatically. We may approve, reject or remove submissions. If approved, the display name, comment, rating and date may appear publicly. Do not enter student names, school identifiers, contact details or classroom records.

Server logs and analytics

Like ordinary websites, the hosting provider may process limited request information such as IP address, browser details, requested path and time to deliver and protect the site. Microsoft Clarity is used to analyze page interactions, navigation patterns and session replays, and to record counts of fixed actions such as starting the meter, encountering a microphone permission block or unavailable device, loading example charts, opening the customizer, presenting voice levels or requesting printable downloads. These custom events send only predefined action names without typed chart labels, class names, audio samples, microphone values or device names. Clicks on download or print controls indicate user requests and do not confirm that a file was successfully saved to disk or printed. Clarity does not receive microphone audio from the meter.

Advertising

No advertising code is active in the initial build. If contextual advertising is added later, this policy will be updated with the relevant provider information and consent behavior. Ads will not receive microphone audio from the tool.

Children and schools

The site does not ask students for names, accounts, messages or other profile information. Teachers and schools remain responsible for device, browser, classroom and consent policies that apply in their jurisdiction.

Contact

Questions or privacy requests can be sent to info@classroom-noise-meter.com. Return to the classroom noise monitor.