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.

Rapid Speech Transmission Index (RASTI) 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. (See also STI).   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). (image): (Sabine's formula)   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.   Speech Transmission Index (STI) <span style="background-color: #ffffff; display: block; font-family: Arial,Verdana,Tahoma,Helvetica; text-align: left;">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. <span style="background-color: #ffffff; display: block; font-family: Arial,Verdana,Tahoma,Helvetica; text-align: left;">