refers to the labor of the speaker to craft, control, or change the expression of feeling in public speaking.

Inflection

Explanation:

The public speaker has to be very aware of his audience as he delivers a speech and deliver accordingly the point they are trying to get across.

Through inflection a speaker changes their feeling and controls their craft to match with audience to deliver the desired effect they want to deliver.

This could be to shock a passive audience or to ride over an enthusiastic one with more aggressive words. It is impromptu and often done through oratory skills.

a factory opens that mass-produces light bulbs.

explanation:

not sure if that's an answer to your questions but this is an example! : )

answer; independent variable;