Sound Level Converter
Convert between decibel scales, sound pressure, and intensity units
Sound Level Converter
Logarithmic ratio of sound pressure to reference pressure
Adjusted to the frequency response of human hearing
Sound Level Context:
Vacuum cleaner, busy traffic
Noise Exposure Calculator
Understanding Sound Levels
Sound level is a measure of the sound pressure or intensity, usually expressed in decibels (dB). The decibel scale is logarithmic, meaning that an increase of 10 dB represents a 10-fold increase in intensity and is perceived as about twice as loud.
Sound Level Units:
| Unit | Description | Typical Use |
|---|---|---|
| dB SPL | Sound Pressure Level, referenced to 20 μPa | General acoustic measurements |
| dBA | A-weighted decibels, adjusted to human hearing sensitivity | Environmental noise, workplace regulations |
| dBC | C-weighted decibels, less adjustment than A-weighting | Low-frequency noise assessment |
| dB HL | Hearing Level, referenced to normal hearing thresholds | Audiometric testing, hearing aids |
Decibel Addition:
Because decibels are logarithmic, they don't add directly. Two identical sound sources together result in a level 3 dB higher, not double. Some rules of thumb:
- Equal sound levels: Add 3 dB (e.g., 60 dB + 60 dB = 63 dB)
- 10 dB difference: Add 0.4 dB to the higher level (e.g., 70 dB + 60 dB ≈ 70.4 dB)
- Greater than 10 dB difference: The higher level dominates
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Sound Level Visualization
Interactive Sound Level Meter
80 dB is 100× more intense than 60 dB
Health Impact
Temporary discomfort: Begins at around 70-80 dB with prolonged exposure
Risk of hearing damage: Starts at 85 dB with prolonged exposure (8+ hours)
Recommended limits:
- 85 dB: Max 8 hours/day
- 88 dB: Max 4 hours/day
- 91 dB: Max 2 hours/day
- 94 dB: Max 1 hour/day
- 97 dB: Max 30 minutes/day
- 100 dB: Max 15 minutes/day
Note: For every 3 dB increase, the safe exposure time is cut in half
Common Sound Levels
Did You Know?
- • The decibel scale is logarithmic: 10 dB is 10 times more intense than 0 dB, and 20 dB is 100 times more intense
- • Human hearing can detect sounds from 0 dB to about 130 dB
- • OSHA requires employers to implement hearing conservation programs when noise exposure exceeds 85 dB averaged over 8 working hours
- • The "loudest" recorded sound was the 1883 Krakatoa volcanic eruption, estimated at 310 dB
- • A-weighting (dBA) reduces the weight of low frequencies to match human hearing sensitivity, which is less sensitive to low frequencies
About the Sound Level Converter
Convert between decibel scales, sound pressure, and intensity units All conversions run instantly in your browser and nothing you enter is sent to a server.
Common Conversion Formulas
| From | To | Formula |
|---|---|---|
| Sound Pressure (P) | Decibel SPL (dB SPL) | dB SPL = 20 × log₁₀(P/P₀) where P₀ = 20 μPa |
| Sound Intensity (I) | Decibel IL (dB IL) | dB IL = 10 × log₁₀(I/I₀) where I₀ = 10⁻¹² W/m² |
| Sound Power (W) | Decibel WL (dB WL) | dB WL = 10 × log₁₀(W/W₀) where W₀ = 10⁻¹² W |