Great Council Chamber Basel
Speech intelligibility rating
To improve the level of speech intelligibility in Basel's Great Council Chamber, a number of changes were made to the chamber itself as well as to the fixtures (installing a carpet, restoring the fold-up chairs, etc.) and the electroacoustic system was upgraded The effectiveness of these changes was monitored using modern measuring techniques to determine the speech transmission index.
This is done by simulating speech with noise of varying pitches that rises and falls at different speeds. In other words, an objective parameter is defined to monitor a subjective criterion such as speech intelligibility and so ensure high quality.
The methodology is defined in standard EN 60268-16 "Objective rating of speech intelligibility by speech transmission index".