Acoustics_Vocabulary

__//**Acoustics Vocabulary**//__
**Acoustics Vocabulary:**

**-Articulation Loss of CONSonants (%-Alcons):** one method of objectively measuring speech intelligibility is Articulation Loss of CONSonants (%-Alcons), showing the number of consonants being missed as a percentage. Consonants play a much more significant role in speech intelligibility than vowels. If the consonants are heard clearly, the speech can be understood more easily. Single value for the laboratory sound attenuation of a suspended ceiling between two rooms according to ASTM E 1414. This measurement takes only into account the sound transmission through the suspended ceiling. Dn,f,w (dB) Single value, according to EN ISO 717-1, for the laboratory sound insulation of a suspended ceiling between two rooms, measured according to ISO 10848-2. This measurement takes only into account the sound transmission through the suspended ceiling. For example, speech, scraping chairs, humming ventilation, traffic, machinery and equipment, sound from corridors, adjoining rooms, playgrounds. Increased background noise can have long-term negative effects, such as illness, fatigue, decreased productivity and efficiency. Therefore
 * -** **Ceiling Attenuation Class (CAC)**
 * -****Background noise (dB)**
 * - Flutter echo:** occurs when noise bounces between parallel surfaces in a room.
 * - Rapid Speech Transmission Index (RASTI):** is an objective way of measuring speech intelligibility. It is measured at two frequencies, 500 and 2000 Hz, by placing a loudspeaker, which transmits sound from the location of the person speaking, and a microphone where the listeners are situated.
 * - 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 pressure level (dB) :** the pressure variations caused by sound waves in air are called sound pressure. The lowest sound pressure level which can be heard is 0 dB, known as the hearing threshold. The highest level which can be tolerated is called the pain threshold and is around 120 dB
 * - Speech Transmission Index (STI):** similar to the RASTI method but a more complete form of measuring speech intelligibility by measuring all octave bands in the frequency range 125-8000 Hz.