Through the use of 3D acoustic models, we are able to predict intelligibility (STI or CIS) during the design phase of a project.  This is helps inform design decisions and in some cases is mandated by the current fire code.  In recent years the general awareness of the importance of speech ineligibility has risen greatly. This is in part due to the large numbers of mass notification and emergency evacuation systems being implemented.

In addition to design phase predictions, GDG is regularly called on to perform third party independent field verification of intelligibility.