This project documents intertalker differences in the acoustic modifications that speakers apply in noisy conditions (clear-Lombard speech, compared to their habitual speaking style). The success of individual speakers' clear-Lombars speech modifications is assessed through acoustic analysis and through human listening effort ratings. The project also tries to find associations between speakers' performance in maximum speech performance tasks (diadochokinesis tasks or tongue twister tasks) and cognitive control performance to shed more light on the question what makes a flexible and intelligible speaker.