Cinemas, schools, conference rooms, recording studios and even personal toilets make use of acoustical material to manipulate, decrease or amplify the sound. The feeling of being part of the action in a cinema hall, and being able to listen to the lecturer speak right in front of the lecture hall would not have been possible without acoustical materials. When architects or builders want to make full use of the space they have, and not allowing the sounds to escape the enclosed area, they look for acoustical materials. The noise can be diffused, echoes can be emitted and vibrations of sounds can be dampened using several types of acoustical materials for different purposes. It is necessary to use these materials in cinemas and recording studios for best sound quality. Uses of acoustical materials can be divided into three categories; for sound proofing, sound absorption and as diffusers of sound waves.
What sound proofing does is that it blocks the sounds from an enclosed space from leaving the area as well as allowing any external sounds from coming into the area. These are commonly used in cinemas and recording studios to enhance the movie experience and get better quality of recording by preventing any unwanted sounds being recorded. Sound proofing can be done on the walls, doors, ceiling and floor. With the enclosed area properly sound proofed, the quality of the sound is enhanced. Also, for example if your house is near a train station, you may want to consider sound proofing as it would keep the noise out from your house allowing you to sleep peacefully at night.
Sound absorption is more commonly used in recording studios as sound proofing does not eliminate the fact that sound wave would reflect on it resulting in echoes and low quality recordings. If sound proofing is used together with sound absorption, it would allow for the best quality of recording. Sound absorption may not only be used in recording studios but even in restaurants. Some restaurant around the world make use of it to decrease the noise of dishes cluttering and people walking to provide a more peaceful environment for their customers to dine in. Absorber materials usually absorb sounds of above 500 hertz. Rigid fiberglass is the most commonly used material to serve as an absorber.
Diffusers are usually applied in enclosed areas that have flat ceilings and walls that are parallel to each other. With this type of structure, the sound waves would simply keep reflecting on the ceiling and walls resulting in an echo. One of the cheapest ways to create a diffuser is by using a few sheets of plywood and placing them at an angle along the wall and the ceiling. The wood also has to be slightly bent. This would cause the sound waves to hit the plywood and get reflected in different directions and thus diffusing the sound.
Diffusers are best used together with sound proofing and sound absorption materials. With all three types of acoustical materials working collectively, the quality of the sound would be greatly enhanced.