*2.4.1 Spaces for speech intelligibility*

Speech clearness is vital in a specific type of functions. Without speech intelligibility, classes' success could fail. Teacher explanations, court sessions, and board meetings are functional, practical examples where speech is the key role of their success. Large institutions need clear discussions to make efficient decisions. In the court, when the speech is not clear, many judicial problems could take part from innocently. Such spaces need clear speech with no reflection nor echoes. In such functions, the number of absorber materials should increase in favor of the reflectors. The absorption material scheme when exceed, will produce a harmful background and thus will require more effort from the sources to enable the audience to hear. Therefore the introduction of some diffusers is necessary to balance the acoustics performance (**Figure 5**).

**Figure 5.** *Examples of classroom, boardroom, and court room where the speech intelligibility needs many absorbers.*
