Echo and Reverberation

The behaviour of the reflected sound plays an important role in sound insulation or acoustical design of room / hall. The main defects which reflected sound waves may cause in a room are : i) Echoes ii) Reverberation should be eliminated.

The effect of Echoes is particularly common when the reflecting surfaces is curved in shape. To minimize this effect in curved walls, the walls of Auditorium are covered with highly absorbent material or grills on the face work.

A certain amount of reverberation is necessary to enhance the sound. However, excessive reverberation is designing to clarify. In this case, the time of reverberation plays a significant role in achieving desired acoustical condition of Auditorium. To control the excessive reverberation, there should apply good resonant absorbants should be applied too the walls of the Auditorium. If the enclosure or auditorium is to be used as sound film theatre or for public address system, the time of reverberation selected should be short.




 Acoustics

Sound insulation of different suitable material provided to certain halls, is termed as Acoustics.
Acoustics is necessary for : i) Cinema theatres ii) Public lecture hall iii) Concert halls and iv) Music studios.
Some of the more important factors which must be considered in the planning of building to obtain satisfactory acoustical conditions are as follows –

1.      Selection of the building site.

2.    Arrangement, dimension and shape of rooms and other planning feature.

3.    Insulation and control sound transmission with in the building.

4. Installation of absorptive materials within the building. In selecting the site for a building for which acoustical consideration are important, attention should be paid to any effect which present or forceable prevailing noises in that area may have on the acoustical condition in the building.

Desirable planning provided as follows –

1. Locate rooms that require a quite environment where they will have the minimum exposures to objectionable outside noises.

2. Provide horizontal and vertical separation of rooms that require a quiet environment from those that are inherently noisy.

3.    Stagger the doorway on the sides of hall or corridor.

4.    Provides doors at the entrances to long corridor, stairway and elevator foyers.

5. Provide appropriate shapes for auditorium, recital hall, music studio and practice room.

6.    Provide room’s sizes acoustically compatible with their proposed uses.