Answer:
Teleprompter.
Explanation:
Teleprompter is a device that is used to display the script for the speaker. It is a device that is hidden from the camera and is placed below or in front of the video camera lens. The screen is made of reflective glasses that enable the presenter or the speaker to view the script.
<u>The use of teleprompter has increased these days. This device helps to speaker, presenter, etc to give the impression that they have memorized the whole script</u>.
So, the correct answer is teleprompter.
On movie sets, they were used to make soundtracks
