Communication accommodation theory

Howard Giles' communication accommodation theory (CAT), "seeks to explain and predict when, how, and why individuals engage in interactional adjustments with others," such as a person changing their accent to match the individual they are speaking with. Additionally, CAT studies "recipients' inferences, attributions, and evaluations of, and responses to, them." This means when speakers change their communication style, listeners are interpreting such alterations.

Source: Wikipedia — Communication accommodation theory (CC BY-SA 4.0)