Last updated: March 2026
What Is a Sound Level Meter?
A sound level meter measures the intensity of sound in decibels (dB), giving you a numeric reading of how loud your environment is. Professional sound level meters are used in workplace safety, construction, event management, and environmental monitoring.
This browser-based sound level meter uses your device's microphone and the Web Audio API to provide approximate real-time dB readings without any app download. While not a replacement for a calibrated instrument, it gives you useful readings for comparing noise levels, checking room acoustics, and general awareness.
The tool supports A-weighting (dBA), which adjusts readings to match human hearing perception and is the standard used in noise regulations worldwide. All audio processing happens locally in your browser — nothing is recorded or transmitted.
How to Measure Noise Levels
Step 1: Tap "Start Measuring" and grant microphone access when prompted by your browser.
Step 2: Hold your device with the microphone unobstructed and pointed toward the sound source.
Step 3: Read the gauge and the large dB number in the center. The color indicates the noise zone: green is safe, yellow is moderate, orange is loud, and red is dangerous.
Step 4: Monitor the peak, average, and minimum readings to understand your noise exposure over time.
Step 5: Export your readings as a CSV file for documentation or analysis.
Understanding Noise Exposure Limits
The National Institute for Occupational Safety and Health (NIOSH) recommends a maximum exposure of 85 dBA for 8 hours. For every 3 dB increase, the safe exposure time is cut in half: 88 dB for 4 hours, 91 dB for 2 hours, 94 dB for 1 hour, and so on.
At 100 dB — the level of a motorcycle or power tool — hearing damage can begin in just 15 minutes. At 110 dB (rock concert front row), damage can occur in under 2 minutes. At 120 dB (ambulance siren at close range), pain is immediate.
An estimated 40 million US adults aged 20-69 show signs of noise-induced hearing loss, much of it preventable. Regular monitoring of your sound environment is the first step toward protecting your hearing.
Frequently Asked Questions
What is a sound level meter?
A sound level meter (SLM) measures the intensity of sound in decibels (dB). Professional SLMs use calibrated microphones and meet IEC 61672 standards. This browser-based version uses your device's microphone to provide approximate readings for general monitoring and comparison — not for legal compliance.
What is the difference between a sound level meter and a decibel meter?
In everyday use, these terms are interchangeable. Both measure sound intensity in decibels. Technically, 'sound level meter' is the formal name for calibrated instruments meeting international standards, while 'decibel meter' is the common term used for general-purpose sound measurement tools.
How loud is too loud for an office?
The World Health Organization recommends office noise levels below 55 dB for focused work. Open-plan offices typically measure 60-70 dB, which can reduce productivity by 15-25%. If your office exceeds 70 dB regularly, consider noise-canceling headphones or talk to facilities management.
How do I measure noise levels in my apartment?
Open this tool, tap Start Measuring, and walk around your apartment. Check levels at different times of day. Common apartment noise complaints involve levels above 60-70 dB during quiet hours. Document readings with screenshots or the CSV export feature if you need evidence for a noise complaint.
What frequency weighting should I use?
Use dBA (A-weighting) for general noise monitoring and hearing safety — it matches how human ears perceive loudness. Use dBC for measuring peak levels from bass-heavy sources like music or machinery. dBZ (unweighted) shows the raw measurement without frequency adjustment.