What are the meanings of the terms found on product information sheets?
Absorption Coefficient (alpha) -The dimensionless ration of absorbed to incident sound energy from a single interaction between a sound wave and a partition. Values range from 0 to 1. Absorption -The product of absorption coefficient and surface area of a material, in units of sabins, used to designate the amount of sound absorbed by that material. -The properties of a material composition to convert sound energy into heat thereby reducing the amount of energy that can be reflected. Frequency (f) -The number of oscillations or cycles per unit of time. Acoustical frequency is usually expressed in units of Hertz (Hz) where one Hz is equal to one cycle per second. -Interpreted subjectively as pitch. Humans can hear sounds having frequencies between 20 and 20,000 Hz. Hertz (Hz) -Frequency of sound expressed by cycles per second. Noise Reduction Coefficient (NRC) -A single number rating system for absorption coefficients over the speech frequency range. The NRC of an acoustical material is
