The world often becomes just too noisy, and you might want to escape it to the top of a tall building or a faraway scene for some peace. But what most people are unaware of is the existence of the world’s quietest places known as anechoic chambers.
What are Anechoic Chambers?
The word anechoic means not echo or having non-reflective qualities. Anechoic chambers are built in such a way that all sound and electromagnetic waves do not bounce back or echo but are instead absorbed by the structure and walls of the room. Aside from preventing the reverb or reflecting of sound created on the inside of the chambers, it also contains any sound or waves from the outside of the room from entering in.
These chambers have sound-absorbing walls as well as floors that are made up of sound-absorbing material. Atop the basal floor level of the chamber, there is a mesh grille that is fitted for people to walk on or for equipment to sit on. These chambers are called full anechoic chambers, whereas those with solid floors are called semi-echoic or Hemi-echoic chambers. These chambers were initially constructed with the sole purpose of eliminating acoustic echo. In contrast, now they can also absorb RF or radiofrequency and are fitted with RAM or Radiation Absorbent Material.
Benefits and Uses of Anechoic Chambers
Since they are highly complicated and challenging to construct, suitable anechoic chambers are only used for research purposes. They are used to conduct acoustic research and are regularly used to develop and innovate more effective automotive, military, and construction vehicles. Some of the experiments conducted in an anechoic chamber measure the directional path of sound and radiation from industrial machines or even a loudspeaker’s transfer function.
The chamber is also used to test the hums and clicks produced by various electronics and audio recording and playing equipment such as mics, headphones, speakers and receivers. This helps inventors and tech geeks to develop more efficient products and computing devices. It has attracted the attention of many organizations and businesses that can pay to use it for testing. It is used primarily by companies that produce medical equipment such as medical defibrillators, hearing aids, sleep-apnea machines, EKG machines, etc. Bettering the accuracy of these medical aids and equipment can be achieved using these rooms.
Features and Testing of Anechoic Chambers
Humans can only hear sounds above 0 dBA, and the highest quality and anechoic efficiency chamber was built to measure -20.6 dBA. Because of this, those who got the chance to enter the sections said that the dead silence provided discomfort and was unsettling to be in for an extended period. They were also able to hear their heartbeat because of the quietness of the chamber. The deafening silence in the room is created by the onion-like structure of the room, six layers of concrete and steel, and fibreglass wedges on all the surfaces of the room. Space sits above a range of noise and vibration dampening springs.
Full anechoic chambers are built to withstand solid sounds and radiation and are used to test heavy test specimens. Hemi-anechoic sections, on the other hand, are used to test those machines and equipment that are typically in an environment with sound reflective surfaces. These thus receive less acoustical treatment and test automobiles, washing machines, construction equipment, fridges and more. Pass/Fail chambers receive the least amount of acoustic treatment compared to the rest as they are only used to test smaller equipment’s acoustic characteristics, such as mobile phones.
Difference Between Acoustic Enclosures and Anechoic Chambers
Now that we have understood all about anechoic chambers and how they are utilized for research and testing purposes, we can see the differences between these chambers and the acoustic enclosures that are more commonly found. Acoustic enclosures are built on a more mass production basis as compared to anechoic sections. This also gives it a higher margin of error or allows for more sound leaks than the rooms. Acoustic enclosures can even be made at home by using foamboards and other soundproofing material.
Another significant difference between the two is the reason for its use. Anechoic chambers are used for industrial-level testing purposes, which brings about its need for accuracy and maximum sound reflection elimination. On the other hand, acoustic enclosures can allow for partial reverb as it is mainly used to reduce noise from the outside for better concentration or quality of life, or even for a quiet environment for music or sound recording and production.