A game theory model of the Lombard effect in public spaces

Abstract

The Lombard effect is the tendency for humans and other animals to raise their vocal intensity in the presence of background noise. As a result, the aggregate effect of many people talking in a public space can lead to multiple equilibria for speech intelligibility, as the incentive for an individual conversation is dependent on the actions of all the other speakers in the space. This system is modeled using game theory, in particular, an n-person Prisoner’s Dilemma model, otherwise known as the Unscrupulous Diner’s Dilemma. It is suggested that conscious knowledge of the dynamics of the system can affect the system's behavior up to a point, but that gradually the subconscious process of the Lombard Effect will cause the system to increase in background noise, only limited by the comfort of each speaker’s voice or an exogenous interrupting event.