Which technique involves altering speech delivery based on audience response during a presentation?

The technique known as adaptive speaking specifically refers to the speaker's ability to modify their delivery style, content, or tone in response to the audience's reactions and feedback during a presentation. This skill is essential for effective communication, as it allows the speaker to engage the audience more fully and address their needs and interests in real time. For example, if a speaker notices that the audience seems confused or disengaged, they might adjust their approach—perhaps by clarifying a point, asking questions, or incorporating anecdotes to recapture attention.

While other options relate to different speaking scenarios, they do not emphasize the responsive nature of altering a speech based on audience feedback. Impromptu speaking involves delivering a speech without prior preparation, which doesn't inherently include adapting to audience cues. Spontaneous speaking also relates to speaking without a planned script but similarly lacks the specific focus on audience responsiveness. Interactive speaking does involve audience participation, but it does not emphasize the level of adaptation to responses in the way that adaptive speaking does. Thus, adaptive speaking is the most accurate term for the technique described in the question.