🔊 Acoustics & Environmental Noise Physics
Sound Pressure Level (SPL) & Decibel Calculator
Compute Sound Pressure Level ($L_p = 20 \log_{10}(p/p_0)\text{ dB SPL}$), acoustic inverse square distance attenuation ($-6\text{ dB}$ per distance doubling), and OSHA safe exposure times.
🤫 Whisper (30 dB)
🗣️ Conversation (60 dB)
🚗 City Traffic (85 dB)
🎸 Rock Concert (105 dB)
✈️ Jet Engine (140 dB)
Source & Distance Inputs
dB SPL
meters (m)
meters (m)
Received Sound Level at Distance (L_p2)
65.00 dB SPL
Sound Pressure ($p$)
0.0356 Pa
Sound Intensity ($I$)
3.16 μW/m²
OSHA Daily Limit
Safe (>8 hrs) 🟢
💡 Acoustic Inverse Square Law:
$$L_{p2} = L_{p1} - 20\log_{10}\left(\frac{d_2}{d_1}\right) = 85 - 20\log_{10}(10) = 85 - 20 = 65.0\text{ dB}$$
Acoustic Decibel Formulas
Sound pressure level is measured on a logarithmic scale relative to human hearing threshold:
- Sound Pressure Level: $$L_p = 20 \log_{10}\left(\frac{p}{p_0}\right) \text{ dB SPL} \quad (p_0 = 20\text{ }\mu\text{Pa})$$
- Distance Attenuation (Spherical Propagation): $$L_{p2} = L_{p1} - 20 \log_{10}\left(\frac{d_2}{d_1}\right)$$
- Distance Doubling Rule: Doubling distance ($d_2 = 2 d_1$) drops sound level by exactly $-6.02\text{ dB}$.