Which term describes a speaker's nervousness gradually declining as their speech progresses?

The term that accurately describes a speaker's nervousness gradually declining as their speech progresses is "adaptation reaction." This concept refers to the body's response to a stressful situation, such as public speaking. Initially, a speaker may experience heightened anxiety as they prepare to deliver their speech, which is a natural physiological response. However, as the speech continues and the speaker becomes more engaged and focused on delivering their message, their anxiety typically decreases. This reduction in nervousness is part of the adaptation reaction, where the body adjusts to the situation, allowing the speaker to become more comfortable and effective in their delivery. This phenomenon is crucial for understanding how speakers can manage their anxiety and improve their performance over time.