This article describes the phonetic process of post-nasal devoicing in Tswana. We propose a multi-agent exemplar model with various interaction schemes which include factors like functional and social biases in order to account for this counter-intuitive phenomenon. Our novel hybrid multi-agent modeling framework facilitates investigation of sound change by combining the sociophonetic model of Nettle [22] and the exemplar-based model of Wedel [26] into a single unified model.