Final answer:
Sam is using the audio element of digital media by adding a voiceover to his class presentation.
Step-by-step explanation:
When script writing and presentations incorporate elements like voiceovers, they utilize the audio aspect of multimedia, which can also include video, images, infographics, and animations. A voiceover specifically harnesses the power of audio to reinforce the content of a script or presentation, enhance understanding, and improve audience engagement. By integrating an audio element, Sam is looking to make an impact on his audience through a sensory experience that complements any visual or textual information presented.