Various types of absorbent materials are available in the market under different trade names. The value of coefficient of absorption is supplied by the manufacturer. Following are some of the most common types of absorbent materials.
- Hair felt : This material was used by Prof. Sabin in his experimental works. The average value of coefficient of absorption of 25 mm thick hair felt is 0.60.
- Acoustic plaster : Also known as fibrous plaster, it includes granulated insulation material mixed with cement. If the quantity of cement is more than that required, the plaster will not have sufficient pores to become effective for acoustics. If the quantity of cement is less than that required then plaster will not have enough strength. ...