dB Meter

1. Click the "Start Measurement" button.
2. Grant browser microphone access permission.
3. The device's microphone will automatically collect and measure sound levels in real-time.
4. Measured data can be downloaded in CSV format.

Decibel (dB) is a logarithmic unit used to measure sound intensity or power levels. It primarily represents ratios, showing how many times greater (or smaller) a value is compared to a reference level rather than representing absolute values.

Characteristics of Decibels

• Logarithmic scale: Since dB uses a logarithmic scale, small numerical changes correspond to large perceptual differences.
  Example: 60dB (normal conversation) → 70dB (vacuum cleaner) → 80dB (traffic noise)
  → A 10dB increase means the sound energy increases approximately 10 times
• Main calculation formula:
  For sound pressure level:
  dB = 20 log10(P / P0)
  ※ P0 is the reference sound pressure (20μPa)
• Matched to human hearing:
  The dB scale aligns with human auditory perception (logarithmic sensitivity), making it ideal for acoustic measurements and noise evaluation.

Sound Level Reference (dB)

Sound Level	Example
10 dB	Breathing sound
30 dB	Library, suburban area at night
50 dB	Quiet office, air conditioner sound
60 dB	Normal conversation
80 dB	Busy traffic road
100 dB	Under train tracks, construction site
120 dB	Rock concert, ambulance siren
140 dB	Near airplane engine (pain threshold)

Precautions

• Sounds above 120dB can risk hearing damage.
• Repeated exposure to sounds over 100dB, even briefly, can cause hearing loss.

In summary, decibel (dB) is an indicator of sound intensity and serves as an important unit for evaluating perceived loudness and safety standards.