Anechoic chamber walkway (grating)

MFAC

In an anechoic chamber (fully anechoic chamber), a grid like the one shown in the photo is installed on the indoor floor. This is called a grating (walkway).

The grating has regular openings on the floor surface, beneath which absorbent spikes are placed. When sound waves from the measurement target hit the floor surface, some pass through the openings of the grating and are absorbed by the absorbent spikes, while some strike the grating itself.

In the photo, the absorbent spikes are not visible because they are covered with a white net to prevent objects from falling.

Anechoic chambers should ideally have no surfaces that reflect sound waves. Therefore, the grating itself is designed in a rounded shape to prevent direct sound wave reflection. This causes sound waves hitting the rounded shape to scatter.

Furthermore, sound waves hitting the grating may cause the grating itself to vibrate and produce self-noise, so it needs to be rigid. Self-noise can adversely affect acoustic measurements in an anechoic chamber.

At Sonora, we design gratings for each project. The base material includes stainless steel and iron, with iron being finished with zinc plating.

Occasionally, tension may be applied to wires stretched around the grating to minimize sound wave reflection. There are also cases where dedicated shoes (similar to the image of a NINJA walking on water) are worn to walk on top of these gratings.