{"chart":"sound-conversion-chart","generatedFrom":"All Unit Conversions shared conversion library","tables":[{"title":"Sound pressure level to pressure and intensity","headers":["dB SPL","Pressure (Pa)","Intensity (W/m²)"],"rows":[["0","2 × 10⁻⁵","1 × 10⁻¹²"],["10","6.325 × 10⁻⁵","1 × 10⁻¹¹"],["20","2 × 10⁻⁴","1 × 10⁻¹⁰"],["30","6.325 × 10⁻⁴","1 × 10⁻⁹"],["40","0.002","1 × 10⁻⁸"],["50","0.006325","1 × 10⁻⁷"],["60","0.02","1 × 10⁻⁶"],["70","0.06325","1 × 10⁻⁵"],["80","0.2","1 × 10⁻⁴"],["90","0.6325","0.001"],["94","1.002","0.00251"],["100","2","0.01"],["110","6.325","0.1"],["120","20","1"],["130","63.25","10"],["140","200","100"],["194","100,200","2.51 × 10⁷"]]},{"title":"Level changes and their meaning","headers":["Change","Meaning"],"rows":[["+3 dB","Double the sound power or intensity (two equal sources together)"],["+6 dB","Double the sound pressure; also the change for halving distance from a point source"],["+10 dB","10 × the intensity; heard as roughly twice as loud"],["−6 dB per doubling of distance","Point source in a free field (inverse-square law)"],["1 Np = 8.686 dB","Neper (natural-log level unit) to decibels; 1 B = 10 dB"]]},{"title":"Adding two sound levels","headers":["Difference (dB)","Add to the louder (dB)"],"rows":[["0","3.0"],["1","2.5"],["2","2.1"],["3","1.8"],["4","1.5"],["5","1.2"],["6","1.0"],["7","0.8"],["8","0.6"],["9","0.5"],["10","0.4"],["11","0.3"],["12","0.3"],["13","0.2"],["14","0.2"],["15","0.1"]]},{"title":"Distance: change in level from a point source","headers":["Distance ratio r₂ ÷ r₁","Point source (dB)","Line source (dB)"],"rows":[["1","0.0","0.0"],["1.5","−3.5","−1.8"],["2","−6.0","−3.0"],["3","−9.5","−4.8"],["4","−12.0","−6.0"],["5","−14.0","−7.0"],["8","−18.1","−9.0"],["10","−20.0","−10.0"],["16","−24.1","−12.0"],["20","−26.0","−13.0"],["32","−30.1","−15.1"],["50","−34.0","−17.0"],["100","−40.0","−20.0"]]},{"title":"A-weighting at octave-band centre frequencies (IEC 61672-1)","headers":["Frequency (Hz)","A-weighting (dB)"],"rows":[["31.5","−39.4"],["63","−26.2"],["125","−16.1"],["250","−8.6"],["500","−3.2"],["1,000","0.0"],["2,000","1.2"],["4,000","1.0"],["8,000","−1.1"],["16,000","−6.6"]]},{"title":"Noise exposure: permitted time per day","headers":["Level (dBA)","NIOSH REL","OSHA PEL"],"rows":[["85","8 h","16 h"],["88","4 h","10 h 33 min"],["90","2 h 31 min","8 h"],["91","2 h","6 h 58 min"],["92","1 h 35 min","6 h 4 min"],["94","1 h","4 h 36 min"],["95","48 min","4 h"],["97","30 min","3 h 2 min"],["100","15 min","2 h"],["102","9 min 27 s","1 h 31 min"],["103","7 min 30 s","1 h 19 min"],["105","4 min 43 s","1 h"],["110","1 min 29 s","30 min"],["115","28 s","15 min"]]},{"title":"Typical sound levels and workplace limits","headers":["Source or limit","Level"],"rows":[["Threshold of hearing","0 dB"],["Quiet bedroom at night","≈ 30 dB(A)"],["Normal conversation at 1 m","≈ 60 dB(A)"],["UK lower exposure action value (daily)","80 dB(A)"],["UK upper exposure action value (daily)","85 dB(A)"],["UK exposure limit value (daily, with hearing protection)","87 dB(A)"],["Rock concert near speakers","≈ 110 dB(A)"],["Threshold of pain","≈ 120–130 dB"]]}]}