TABLE OF CONTENTS Acoustics is the science of sound and vibration. The control of sound and vibration transmission within a structure involves architectural design and structural, mechanical, and electrical engineering considerations. The end result of a building where acoustical and vibration control is taken into account during design and where these considerations are carried out by the contractor results in the creation of an environment in which people can live and work more comfortably and productively.
Sound is a vibration that occurs at various frequencies in an elastic medium. It is generated at a source and it travels through either a gaseous, liquid, or solid environment. Sound-pressure levels are represented in decibels a ratio of intensity of sound, as measured to an intensity equivalent to the threshold of hearing. Changes in decibel levels do not follow arithmetic progressions (e.g., a change in 10-db pressure will result in the perception of hearing sound twice as loud). However, a change of 3 db, up or down, will be barely perceptible. Resistance to sound transmission varies with different frequencies. The span of human hearing ranges from 15 Hertz (Hz) to 20,000 Hz. Sound transmission coefficient factors (STC) are tested at frequencies in the 125- to 4000-Hz range.
The American Society of Interior Designers (ASID) hired the Yankelovich Partners in 1996 to determine if noise-level reduction was of major concern to office workers. Seventy percent of the respondents indicated that their productivity would increase if they...
