You watch a movie with some scenes set in a noisy bar, some scenes containing gunfire, and some scenes containing very quiet dialogue. the noisy scenes are very loud, and during the quiet scenes you can hear most of the dialogue, but you find that if the actors drop their volume on certain lines, you cannot hear what they are saying. this reflects the fact that a message must exceed the in order to be processed.

I believe the answer is: Threshold

In communication process, volume threshold refers to the bare minimum of volume power that needed for a message to be transferred from one person to another. The threshold within communication mainly influenced by two factors, the voice volume of the sender and the noise level within the environment surrounding the communicators.

answer; the cats meowing will temporarily increase, but then it will decrease;