Total sound power is a spherical area-weighted sum over full orbitals around a speaker

Evidence

In addition to the direct sound (the on-axis response) there is an energy sum of first reflections from the floor, ceiling and side walls derived from the appropriate anechoic off-axis responses, assuming spectrally perfect reflections and including inverse-square law attenuation. There is also an estimate of the contribution made by the total radiated sound power, calculated from a spherical area-weighted sum of measurements made on 360° horizontal and vertical orbits around the loudspeaker, modified according to the frequency dependent absorption in the room revealed in reverberation-time measurements. — Toole, Floyd E, Sound reproduction- the acoustics and…, 183

Categorization

• DEFINE: Clarifies that total radiated sound power is defined as a spherical area-weighted sum of orbit measurements, with room absorption applied via reverberation-time data.