Acoustic pole of reflected waves

Professional Definition

The field of reflected waves is the area of the acoustical field where the energy of the reflected waves is greater than the energy of the direct wave.

This phenomenon occurs after exceeding the so-called critical distance from the sound source. In this zone, the density of acoustic energy coming from multiple reflections off the walls, ceiling, and floor exceeds the energy arriving directly from the source. In ideal conditions (diffusion field), the energy density in this area is uniform at every point, and the direction of energy flow is statistically even in all directions.

Acoustics in Simple Words

Imagine that you are standing in a dense crowd at a party. When you talk to a person standing right next to you, you can hear them clearly. But if you try to listen to someone from the other end of the room, their voice blends with the general buzz of conversations reflecting off the walls. This general buzz that fills the room and has no clear direction is analogous to the field of reflected waves. In this zone, you no longer hear the “pure” source, but the room's response to that sound.

Summary

The field of reflected waves is the zone of a room where the acoustics of the interior dominate over the direct sound from the source. Its control is essential to avoid “reverberation noise,” which destroys the intelligibility of speech and music.