Sound proof construction! Characteristics (2023)

Sound Proof Construction

Some materials having hard, rigid including non-porous surfaces, provide the least absorption, whereas these which are flexible, soil porous also can vibrate, and absorb more extra sound
The efficiency of the sound absorption depends upon the porosity of every material used essentially sound absorbent
The term used to express the percentage of the incident sound that can be absorbed by a material is known as the absorption coefficient of the material
If the absorption coefficient of a material is 0.75, means that the material is capable of absorbing 75 % of the incident sound
Each absorption coefficient changes with the frequency of every incident sound
low-density materials have a higher absorption coefficient

When sound waves strike the surface of a porous material, a part of the waves make reflected while a component enters the pores of the material including dissipated within heat energy
These efficiencies of this sort of absorbent increase with the increase in the resistance granted by the material
It is used to absorb sound having a high frequency

Some absorbent material is fixed toward sound framing timber with an air space between each framing including the wall near the back.
Such an arrangement runs most efficiently during absorbing sound waves at a base frequency
This principle of sound absorption is that sound waves of the appropriate frequency cause sympathetic vibrations in the panel which serves to be a diaphragm
Some absorption of sound uses placed under the dampening of some sympathetic vibration.
The dampening effect of this system can be improved by placing a porous material in the air space.

It essentially consists of a chamber with a narrow opening (entrance) in which absorption takes place by the resonance of the air in the chamber which gives a loss of sound energy
Such an arrangement container work effectively over a single picked frequency.
Application of cavity resonator is usually restricted to absorption from an individual machine or in similar cases

They consist of perforated panels mounted on battens to leave a cavity between the panels and the wall at the back
The panels may be of metal, wood (plywood) hard broad, plasterboard, etc
The range of holes in the panel should differ between 10 to 20 % of each total area of the panel.
When some sound strikes the panel, the sound waves pass through the holes and also get damped through the resonance of the air in that cavity.
The effectiveness of that system can be increased by placing a porous material same mineral wood etc. in this cavity
This type of absorbent is commonly used, as it is easy to install, economical and it can accommodate a wide range of frequencies

The intensity of sound is defined as the amount of flow of wave energy crossing per unit of time through a unit area taken perpendicular to the direction of propagation.
Some loudness about sound is described as the degree of sensation.
Which is not a wholly physical quantity but partly subjective & does not depend upon the ear & listener.

Frequency or pitch is defined as the number of cycles that a sounding body makes in each unit of time.
It is a measure of the quantity of sound.