Acoustics+Vocabulary

Background noise (dB) For example, speech, scraping chairs, humming ventilation, traffic, machinery and equipment, sound from corridors, adjoining rooms, playgrounds.

Flutter echo Occurs when noise bounces between parallel surfaces in a room.

Frequency (f) 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.

Noise Unwanted sound. Noise can often be the individual perception of a particular sound, e.g. a background noise.

Sabine The physicist Wallace Clement Sabine (1869-1919) created in Riverbank, west of Chicago, the well known Sabine formula (T=0,16V/A), showing the relationship between reverberation time (T s), room volume (V m³) and the amount of absorption (A m²).

Sound absorbers Materials and structures with the ability to take up sound energy and convert it into other forms of energy. They improve room acoustics by removing sound reflections, thus reducing the noise and the reverberation time.

Sound insulation The ability of a building element or building structure to reduce the sound transmission through it. The sound insulation is measured at different frequencies, normally 100-3150 Hz.