Sound Level Logger
Graphs your microphone's volume over a whole lesson as a live scrolling line chart, with running min, average, and max stats plus a one-click CSV export for class data projects.
Built by the AbraCalc team
How to play
- Tap Turn on microphone and allow access when your browser asks.
- Watch the scrolling chart and the min/average/max stats update as the lesson runs.
- Tap Turn off microphone at any point — the logged readings stay on screen for review.
- Tap Export CSV to download the logged readings as a spreadsheet-ready file, or Reset log to start a fresh session.
Turn on the microphone and this tool quietly logs the room's volume twice a second, drawing it as a live scrolling line chart while running min, average, and max numbers update beside it. It's built for a simple classroom inquiry: how loud is our class during silent reading versus group work, and does it change over the lesson? When you're done, tap Export CSV to download the logged readings as a spreadsheet-ready file with a timestamp and volume column, ready to drop into a spreadsheet or graphing exercise. As with every AbraCalc microphone tool, the audio itself is analyzed live in the browser and never recorded or sent anywhere — only the plain volume numbers are kept, and even those live only in this browser tab until you export or reset them.
Frequently asked questions
- Does this tool save or upload the actual classroom audio?
- No. The microphone signal is analyzed live in your browser to measure loudness only, and only the resulting volume number is logged. The raw audio is never recorded, stored, or sent to any server.
- What's in the CSV file when I export it?
- Two columns: seconds since the log started, and the volume level at that moment on a 0-100 scale, with one row per reading taken roughly twice a second. It opens directly in any spreadsheet program for graphing or analysis.
- Is there a limit to how long I can log for?
- The log keeps the most recent 2,000 readings, which covers roughly 16 minutes of continuous logging. Beyond that, the oldest readings roll off to make room, but every exported timestamp stays true to the real elapsed time — the CSV simply starts at the oldest reading still in the log.