This study investigates the application of voice recognition technology to online lectures focusing on the efficacy of the text component of a multimedia presentation. Specifically, participants were provided with online access to multimedia instructional packages comprising an image of the lecturer with accompanying computer slides, plus simultaneous scrolling text of the words spoken during the lecture. Participants' knowledge was measured before and after the lecture presentation. Contrary to cognitive load theory, the results did not show a negative redundancy effect, that is, there were no differences in learning efficacy between the conditions with and without on-screen text. Further, participants found no difference between text edited for semantic breaks compared to unedited text. The implications for online instructional design are that resources are better spent providing a combination of audio and slides rather than text and slides, and that if text is provided then editing for semantic line breaks is not warranted. (Contains 3 tables and 1 figure.)