The Reverse Redundancy Principle, however, suggests that the same coupling of audio and visual information, can have a positive effect on comprehension when the message is being delivered in a non-native language, as they process their second language differently than a native speaker might. This principle is already incorporated into successful language learning softwares like Rosetta Stone.
In a pre-test post-test comparison of learning gains (shown in table below), we see that both students taught primarily through text, and those taught primarily through verbal instruction, both exhibited significantly higher test scores when exposed to instruction incorporating the redundancy principle.