Abstract
Measurements of Articulation Index were made in a car cabin in order to determine the spatial variation of speech intelligibility. The resulting mappings are shown for two types of sound source: an omnidirectional loudspeaker and a loudspeaker whose directivity is thesame as that of a human speaker. These measurements are compared totwo models of sound field: a free field and a diffuse one. The conclusions are that, for an omnidirectional loudspeaker, the sound field in the compartment is almost perfectly free. For a human speaker, it is intermediate between those two models. Therefore, the car cabin can increase the intelligibility of speech, especially when emitted by the driver and listened to by the rear passengers. (A).