A anechoic chamber is a special acoustic test room whose walls are designed in a way that they reflect almost no sound. The low-reflection room of the institute complies with ÖNORM S 5035.
The visible damping elements are wedge-shaped and made of porous material. Since the absorption capacity of these wedge elements decreases towards low frequencies for wave theoretical reasons, the following combination of absorption measures was applied:
- porous wedge absorbers with a base area of 28 x 28 cm and a length of 90 cm,
- Cut-off frequency approx. 100Hz
- Hole absorber with cavity damping for absorption peak widening and with a resonance
frequency of 118 Hz
- 3 types of Helmholtz resonators with resonance frequencies of 31 Hz, 55 Hz and 90 Hz
The sound absorption capacity is increased by the intended hole and Helmholtz absorbers in such a way that the Helmholtz resonators, which are effective up to approx. 31 Hz, favourably shift the cut-off frequency downwards.
With the help of a rail system provided in the test room, grand pianos and as well heavy-weight optical tables can be moved into the room easily.
In connection with the low-reflection room, a large number of measurement and studio microphones as well as digital recording devices with up to 32 channels are available.