A High Accuracy, Low-latency, Scalable Microphone-array System for conversation analysis
Understanding and facilitating real-life social interaction is a high-impact goal for Ubicomp research. Microphone arrays offer the unique capability to provide continuous, calm capture of verbal interaction in large physical spaces, such as homes and (especially open-plan) offices. Most microphone array work has focused on arrays of custom sensors in small spaces, and a few recent works have tested small arrays of commodity sensors in single rooms. This paper describes the first working scalable and cost-effective array that offers high-precision localization of conversational speech, and hence enables ongoing studies of verbal interactions in large semi-structured spaces. This work represents significant improvements over prior work in three dimensions – cost, scale and accuracy. It also achieves high throughput for real-time updates of tens of active sources using off-the-shelf components. We describe the system design, key localization algorithms, and a systematic performance evaluation. We then show how source location data can be usefully aggregated to reveal interesting patterns in group conversations, such as dominance and engagement.