Here's why:
* Speeches are live: A speech is a live performance, delivered in real-time. This allows for immediate feedback from the audience, which can influence the speaker's delivery and even the content of the speech.
* Essays are static: Essays are written and published, with no opportunity for direct interaction between the writer and the reader. The reader can't interrupt, ask questions, or react in real-time.
This interaction is reflected in several speech-specific techniques:
* Eye contact: Speakers look directly at their audience, making a connection and gauging their reactions.
* Body language: Gestures, posture, and facial expressions add emphasis and emotion to the message.
* Voice modulation: Speakers use variations in volume, pitch, and pace to keep the audience engaged.
* Audience engagement: A speaker might ask questions, use rhetorical devices, or address specific individuals to keep the audience involved.
While essays can certainly be engaging and persuasive, they lack the dynamic, real-time element that defines a speech.