Speech communication under unfavourable acoustic conditions means that a larger part of the limited working memory resources must be allocated to the phonological coding of the speech. Less resources therefore remain for the further processing of speech: integration of current information with previously presented parts of the speech and with permanently stored information and the more permanent storing of new information. Effects of reverberation time on the listener’s cognitive load and learning are discussed from this perspective. Studies are needed of reverberation effects in realistic long-lasting speech communication situations to better understand the effect of RT on speech communication.