ACOUSTICS



ACOUSTICS DEFINITIONS Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics technology may be called an acoustical or audio engineer. The application of acoustics can be seen in almost all aspects of modern society with the most obvious being the audio and noise control industries



**SPEED**: is the distance travelled in unit time (m/s) by a sound wave.The speed of sound depends on the medium the waves pass through, and is a fundamental property of the material. In general, the speed of sound is proportional to the square root of the ratio of the elastic modulus (stiffness) of the medium to its density.



**FREQUENCY:**number of complete waves in one second. This is measured in Hertz (Hz). Stated in Hz (hertz). The higher the value, the lighter the tone (bass - treble). The frequency of speech lies primarily between 125 and 8000 Hz, while audible sound lies between 20 and 20 000 Hz.

Interzone Attenuation of Ceiling Systems The measurement of interzone attenuation demonstrates the sound reflective characteristics of ceiling systems when used in conjunction with partial-height space dividers.  The frequency range which can normally be heard by humans lies between 20 and 20,000 Hz.

**WAVELENGHT:** distance between matching points on the wave. This is sometimes called lambda and it is measured in metres (m).

**LONGITUDINAL**: vibration parallel to direction of travel.

**TRANSVERSE**: vibration at right angle to direction of travel.