Every time we interact, our personal space is being negotiated. It is a subtle and intuitive dance that only becomes conscious when someone puts a foot wrong and leans in too close, smells too strongly, speaks too loudly. We generally measure the size of our private bubble in terms of physical proximity. But today, technology is rewriting these complicated dance steps in another sphere: It’s not where we stand but what we hear when we are in close proximity that is changing.

Personal space is at the heart of how we communicate with one another, and how we define it has society-wide ramifications. It has been described by neuroscientist Michael Graziano as a “second skin”—a spatial scaffold that affects our interactions. Yet there has been relatively little interrogation of how...