Studies investigating learning gains in students exposed to synthetic voice audio-narration versus natural voice audio-narration have yielded mixed results. Hence this study was designed to further explore learning gains in an educational setting using synthetic voice audio-narration. The aims of the study were to quantitatively assess learning gains in students exposed to an educational resource narrated in a synthetic voice using Text-to-Speech, as compared to a natural voice narrated one and to qualitatively compare the two learning resources by using the following criteria: helpfulness, quality, warmth and familiarity and preference of audio-narration. This study consisted of 3 experiments.
Experiments 1 and 2 were designed to compare a synthetic voice-narrated learning resource against a natural voice-narrated learning resource. Experiment 3 was designed to investigate learning gains and qualitative factors in a face-to-face narrated presentation. For Experiments 1 and 2, presentations were prepared in Microsoft PowerPoint 2007 to include synthetic voice audio-narration by using the freely available Text to Speech software “PowerTalk 1.2.14”. Natural voice audio-narration was done by recording the tutor’s voice in the PowerPoint. Student’s two-tailed t-tests were used to compare differences in samples.
There was no significant difference in learning gains in students using a learning resource with synthetic voice audio-narration as compared to a natural voice audio-narration. Regarding the quality of audio-narration, results suggested that natural voice narration and face-to-face narration were perceived to be of higher quality that synthetic voice narration. Although all learning resources were perceived as being helpful, students preferred face-to-face narration with a PowerPoint presentation by the lecturer as their first choice followed by the narrated Power Points whilst PowerPoint presentation only was the third choice. This study shows that synthetic voice audio-narrated resources could be a useful tool in educational settings.