Decibel Meter Online


Clip
-∞
dBA
 
Min -∞ dB
Avg -∞ dB
Max -∞ dB
Peak -∞ dB

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Reference Sound Levels (Approx. dB SPL)

    About This Tool

    This online tool functions as a sound level meter, measuring and analyzing audio in real-time using your device's microphone. It offers advanced features for sound analysis, including multiple measurement scales, real-time visualizations, and accurate sound measurements, making it ideal for both casual users and professionals who need to monitor environmental noise levels.

    Key Differences in Measurements (dBFS vs. dB SPL)

    This tool uses dBFS (Decibels relative to Full Scale), which measures the digital signal level captured by your microphone. The 0 dBFS represents the point at which the signal begins to clip (distort). Importantly, dBFS is not the same as dB SPL (Sound Pressure Level), which is a physical measurement of sound intensity, and requires calibrated equipment like a dedicated SPL meter for accuracy.

    This tool is designed for relative measurements, where you can compare sound levels over time or across different environments. It's a software-based solution that continuously updates and improves to give you a practical way of monitoring noise levels in real-time.

    Factors Affecting the Readings:

    • The quality of the microphone used, including its frequency response and sensitivity.
    • Device internal settings such as microphone gain or volume.
    • Distance between the sound source and the microphone, as well as the angle of the microphone.
    • The presence of background noise, which can influence readings.
    • Operating system and browser settings that might apply audio processing like Automatic Gain Control (AGC), noise suppression, or echo cancellation.

    Keep in mind that this meter is most effective for tracking relative sound levels, such as comparing the loudness between different moments or environments. It should not be used as a primary method for precise sound measurement.

    Accuracy and Calibration Features:

    • Weighting (dBA/dBC/dBZ): Standard frequency weighting curves are applied using FFT analysis. dBZ represents a flat (unweighted) response, while dBA and dBC adjust the readings to reflect human hearing sensitivity (dBA) or low-frequency content (dBC).
    • Calibration Offset: The tool allows you to add or subtract a fixed dB value to match a reference SPL meter at a specific frequency or distance. This is particularly useful if you have access to an actual SPL meter for calibration.
    • Clipping Indicator: This feature warns you when the audio signal approaches the maximum limit (0 dBFS), indicating potential distortion.
    • Min Reading Delay: To ensure accuracy, the tool ignores any initial startup sounds or background noise, and starts measuring after 1 second.

    Troubleshooting

    Meter Not Starting or No Sound

    • Ensure microphone permissions are enabled in your browser settings.
    • Verify correct microphone is selected.
    • Close other apps using the microphone.
    • Try refreshing or restarting the browser.

    Inaccurate Readings (Too High/Low)

    • Adjust your microphone input volume.
    • Change distance to the sound source.
    • Use Calibration Offset for better accuracy.

    Meter Stops Unexpectedly

    • Browser or OS may interrupt the mic. Restart the tool.
    • Try simpler graphs on older devices.

    Performance Issues or Slowness

    • Lower "Display Update Rate" in settings.
    • Use "History" or "Current Level" instead of complex visualizations.
    • Close unused tabs and apps to free up system resources.

    Additional Tips for Best Readings

    • Audio Enhancements: Disable AGC, noise suppression, or echo cancellation if possible.
    • Microphone Placement: Keep a consistent position and angle for the mic.
    • Background Noise: Use in a quieter environment for best results.
    • iOS Users: Add +10% offset for more accurate results.
    • Calibration with SPL Meter: Use known source and calibrate accordingly.

    Understanding the Visualizations

    This tool provides real-time charts, FFT spectrum displays, and progress bars to help you visualize the sound environment. These make it easier to observe noise changes and specific sound events.

    Advanced Features

    • Real-Time Display: Live updates of sound level.
    • Peak Hold: Shows the highest sound level reached.
    • Multiple Graph Types: Choose from history, bars, or frequency spectrum.
    • Custom Calibration: Align with SPL meters for improved precision.

    Limitations of the Tool

    • Microphone Quality: Built-in mics may lack accuracy.
    • Calibration Needs: Relative readings only unless calibrated.
    • Environmental Variability: Factors like wind or acoustics can affect accuracy.