Natural Versus Synthesized Voice
Instructors have the option of lecturing with the human voice or a computer-generated voice. In a study involving a lecture on lightning formation, students learned better from the recorded human voice than the Microsoft text-to-speech software [§22 Atkinson et al., 2005]. This finding aligns with the voice principle, which asserts that the human voice is superior to a computer-generated voice for lecturing [§22 Mayer et al., 2003]. However, improvements to voice synthesis technology have made computer-generated voices similar to or better than human voices for learning [§22 Craig and Schroeder, 2017].