Synthetic versus human voices in audiobooks: The human emotional intimacy effect

Human voices narrate most audiobooks, but the fast development of speech synthesis technology has enabled the possibility of using artificial voices. This raises the question of whether the listeners’ cognitive processing is the same when listening to a synthetic or a human voice telling a story. This research aims to compare the listeners’ perception, creation of mental images, narrative engagement, physiological response, and recognition of information when listening to stories conveyed by human and synthetic voices. The results showed that listeners enjoyed stories narrated by a human voice more than a synthetic one. Also, they created more mental images, were more engaged, paid more attention, had a more positive emotional response, and remembered more information. Speech synthesis has experienced considerable progress. However, there are still significant differences versus human voices, so that using them to narrate long stories, such as audiobooks do, is difficult.