Analysis of sound activities and voice activity detection using in-car microphone arrays

In this study, we evaluate the collaboration of multiple microphone arrays installed in the interior of a car, with the aim of robustly identifying the driver's voice activities embedded in car environment noises. We first conducted preliminary analysis on the identified sound activities from the sound direction estimations by different microphone arrays arranged under the physical constraints of the car interior. Driving audio data was collected under several car environment conditions, including engine noise, road noise, air conditioner, winker sounds, radio sounds, driver's voice, passenger voices, and external noises from other cars. The driver's voice activity intervals could be identified with 97% detection rate by combining two microphone arrays, one around the “eyesight” camera system cover and the other around the driver's sun visor.