← Equation Book
Noise
10 equations
NO-01
Permissible Exposure Duration (5 dB Rule)
ASP CSP Foundational
Determine the maximum time a worker may be exposed to a given noise level under OSHA's 5 dB exchange rate.
NO-02 Noise Dose
ASP CSP Foundational
Calculate the cumulative noise dose as a percentage of the permissible limit. D ≥ 100% requires action.
NO-03 TWA from Dose
ASP CSP Foundational
Convert a noise dose percentage into an equivalent 8-hour TWA exposure level in dB.
NO-04 Sound Intensity
ASP CSP Advanced
Calculate the acoustic intensity from sound pressure. Used in free-field conditions.
NO-05 Combined Sound Pressure Level
ASP CSP Advanced
Calculate the total sound pressure level when multiple noise sources are combined.
NO-06 Sound Power Level
ASP CSP Advanced
Calculate the sound power level of a source in decibels relative to the reference acoustic power.
NO-07 Sound Pressure Level
ASP CSP Advanced
Convert measured sound pressure to decibels relative to the threshold of hearing.
NO-08 Inverse Square Law — Distance
ASP CSP Foundational
Calculate how noise level changes with distance from a point source in a free field.
NO-09 Room Noise Reduction (Absorption Treatment)
ASP CSP Advanced
Predict the noise reduction achieved by adding sound-absorbing material to a room.
NO-10 Duct Liner Noise Reduction
ASP CSP Advanced
Predict noise reduction per foot of duct length when duct is lined with acoustic material.
