🔊 Sound Level Meter

Online sound level meter that measures and displays decibel values in real-time from your microphone. Supports graph display.

When you grant microphone access, you can measure volume in real-time.

Audio data is not sent to any server. All processing is done within your browser.

Noise Level Guide

level dB Sound Examples
Quiet20-30 dBWhisper, residential area at midnight
Quiet30-40 dBLibrary, quiet park
usually40-50 dBQuiet office, air conditioner
usually50-60 dBNormal conversation, TV sound
Moderately Loud60-70 dBVacuum cleaner, noisy office
Moderately Loud70-80 dBMain road, piano practice
Loud80-90 dBInside train, factory, pachinko parlor
Very Loud90-100 dBKaraoke, dog barking
Dangerous100+ dBLive concert, jet aircraft

Usage and Application Examples

  • Click the "Start Measurement" button to grant microphone access
  • Decibel values are displayed on the gauge in real-time
  • You can view the volume trend over the past 30 seconds in a graph
  • Analyze measurement results with maximum, minimum, and average values

Features

  • Real-time Measurement — Instantly calculate and display decibel values from microphone input
  • Color-coded Level Display — 4 levels: Quiet (Green), Normal (Yellow), Somewhat Loud (Orange), Loud (Red)
  • Time Series Graph — Visualize the volume trend over the past 30 seconds with a Canvas line chart
  • Statistics Display — Automatically calculate maximum, minimum, and average decibel values
  • Privacy Protection — Audio data is processed within the browser. No transmission to external servers.

Use Cases

  • Noise Check — Quickly measure noise levels at home or office. Measure soundproofing effectiveness.
  • Volume Adjustment — Use as a reference to check if musical instruments or speakers are at appropriate levels
  • Education & Learning — Learn the relationship between sound volume and dB values through hands-on experience

What is Sound Level Meter?

Sound Level Meter is an online application that measures ambient noise and displays decibel levels in real-time using your device's microphone. Perfect for monitoring sound levels in work environments, venues, or personal spaces, this tool provides immediate audio feedback with visual graphs and numeric readings. No specialized equipment needed—just browser access and microphone permission.

How to Use

Grant microphone permission when prompted by your browser. The meter begins capturing and analyzing ambient sound immediately. A real-time display shows current decibel levels, with visual indicators and numeric values updating continuously. The application typically displays peak levels, average levels, and a frequency graph showing which sound frequencies dominate your environment. Adjust the microphone input level if readings seem inaccurate. Most sound meters display historical data as a graph over time, allowing you to observe noise patterns. Calibration notes appear on screen indicating ranges like quiet office or loud traffic to contextualize your readings. Export or screenshot data for records when needed.

Use Cases

Workplace safety compliance requires regular noise monitoring in factories, construction sites, and industrial facilities—this tool provides quick baseline readings. Event venues use sound meters to ensure music and speech levels meet venue regulations and guest comfort standards. Recording studios monitor ambient background noise to maintain quality audio capture for music or podcasts. Musicians test practice space acoustics and sound isolation effectiveness before expensive equipment installation. Sleep researchers track environmental noise patterns affecting rest quality. Teachers monitor classroom noise levels to optimize learning environments. Home office workers identify disruptive sound sources affecting focus and productivity. Legal noise complaint documentation benefits from timestamped digital measurements.

Tips & Insights

Decibel scales are logarithmic, not linear—every 10 dB increase represents ten times more sound energy. Common references: 30 dB (whisper), 60 dB (normal conversation), 85 dB (city traffic), 100 dB (motorcycle), 140 dB (threshold of pain). Professional sound meters cost hundreds; browser-based versions provide reasonable accuracy for general monitoring but lack professional calibration. Microphone quality affects accuracy—built-in device microphones have limitations compared to external USB microphones. Consistent measurement position matters: angle, distance, and surrounding reflective surfaces influence readings. Extended noise exposure above 85 dB causes hearing damage—regular monitoring protects long-term hearing health.

Frequently Asked Questions

How accurate is this sound level meter?

This tool uses your browser's Web Audio API and device microphone for basic measurement. Accuracy may vary depending on microphone sensitivity and device characteristics. For precise measurements, please use a dedicated sound level meter.

Is microphone access permission required?

Yes. Your browser will prompt you to allow microphone access. Select 'Allow' to start measuring. Audio data is never sent to a server - all processing happens locally in your browser.

What is a decibel (dB)?

A decibel (dB) is a unit that measures sound loudness (sound pressure level). 0dB is the quietest sound a human can hear, 30dB is a whisper, 60dB is normal conversation, and 80dB or higher is considered loud.

What does the measurement graph show?

It displays a line graph of decibel values over the past 30 seconds. The horizontal axis represents time and the vertical axis represents dB value, allowing you to monitor sound level changes in real-time.

Can I use it with my smart phone?

Yes. You can use it on any smartphone or tablet with a microphone in browsers like Chrome and Safari. However, accuracy may vary depending on the device's microphone quality.

What is the measurement range of this sound level meter?

Browser-based sound level meters typically measure from approximately 30 dB (quiet background) to 100+ dB (very loud sounds). The exact range depends on your microphone's quality and capabilities, with very quiet or extremely loud sounds potentially being inaccurate.

How frequently does the meter update its readings?

The sound level meter updates measurements typically 10-30 times per second to provide real-time responsiveness. This fast refresh rate lets you see immediate reactions to sudden loud noises or changes in ambient sound levels.

What are typical sound level examples for reference?

Quiet library (30-40 dB), normal conversation (50-60 dB), busy street (70-80 dB), vacuum cleaner (80-85 dB), and rock concert (100+ dB) are useful reference points. Levels above 85 dB can cause hearing damage with prolonged exposure.

Why does the meter reading jump around constantly?

Sound levels naturally fluctuate due to background noise, air movements, and microphone sensitivity to ambient vibrations. These fluctuations accurately reflect real-time variations in sound pressure, not a meter malfunction.

Can I record or log sound level measurements over time?

Most basic implementations don't offer built-in logging, but you can manually record peak measurements or use browser developer tools to capture data. Screenshotting or note-taking during your measurement session preserves your findings for later review.

What microphone quality affects measurement accuracy?

Built-in laptop and smartphone microphones work adequately for general use, while external USB microphones with flat frequency responses provide significantly more accurate readings. Professional-grade measurement microphones offer the highest precision if accuracy is critical for your application.