Click on link: http://politiken.dk/tv/ECE2307233/kom-med-i-lydlaboratoriet/ and see sound expert Associate professor Finn Agerkvist demonstrate the different types of acoustic measurement rooms at DTU Elektro.
Acoustics is all about sound, how it is generated, how it spreads and how it is perceived by human beings. Engineering acoustics deals with how to measure, control and improve sound in many different contexts. Sound plays a big role in our day to day lives and having a knowledge of acoustics can have a big influence in how one improves the sounds surrounding us. This includes both sounds we enjoy, for example improving the sound quality of a loudspeaker or having a better understanding of speech for the hard of hearing, or reducing sounds we find irritating like for example cars, airplanes or improving the acoustics in a room or a building.
Finn demonstrates the strong echoes in the reverberation room due to its hard walls and the ‘dead’ acoustics of the anechoic chamber due to absorbing walls. Both rooms are used to examine and research sound and acoustics.
The reverberation chamber creates a diffuse (random) incidence sound field, so that sound is coming from all directions at all times. The room is used to measure absorbing materials and the sound power of sources.
The "sound dead room" is a room designed to completely absorb the sound and the walls so that no reflections are generated. This means that conduct acoustic experiments under so called "free field" conditions can be performed, this is a major advantage since the free field condition is very simple to model mathematically in order to avoid disturbance from exterior sources of noise, the room also has excellent acoustic insulation.
Kilde: Politiken TV / Jacob Ehrbahn og Martin Friis