Use this calculation for a first-order acoustics estimate when the stated geometry, propagation model, averaging convention, reference quantity, and SI units match the measurement or design problem.

Intensity Watts Per Square Meter

A finite measured or assumed value greater than or equal to 0, expressed in W/m2.

Speed Meters Per Second

A finite measured or assumed value greater than or equal to 0, expressed in m/s.

The implemented rule is: Acoustic energy density of a traveling plane wave from intensity divided by propagation speed.^[1]

Joules Per Cubic Meter

The calculated joules per cubic meter, expressed in J/m3.

This is an idealized calculation rather than a complete acoustic simulation or measurement. Reflections, boundary conditions, directivity, damping, frequency dependence, near-field behavior, background noise, transducer response, temperature, humidity, and geometry can change a real result.

Confirm important results with calibrated measurements or a model that includes the actual geometry, materials, boundaries, source directivity, and frequency-dependent losses. Preserve the reference quantity and weighting whenever a result is expressed in decibels.

• Acoustic Intensity From Spl

  Plane-wave free-field intensity from sound-pressure level, assuming the conventional 10^-12 W/m² reference.

• Acoustic Power From Intensity Area

  Acoustic power crossing an area under uniform normal incidence.

• Intensity Level From Intensity

  Sound-intensity level in dB relative to 10^-12 W/m².