Math would dictate it's approximately 1/2 the volume, since four parts of the board are changing at once for the full logo, but two parts at once for a single answer.
It would be
significantly less than half the volume of the whole board flip-flopping for the Family Feud word logo.
Looking at the close-up picture of the board:
Each character is five dots wide and seven dots tall. That's 35 dots that need to flip to black per revealed letter, minus however many dots remain in their "lit up" state to form the letters for the word. Even for a non-answer, that's a total of 385 dots flipping (11 characters allowed * 35 dots per character).
When the board is doing the full-screen "Family Feud" flip-flop, there are 8,400 dots (30 characters * 8 rows * 35 dots per character) changing state.
8,400 dots changing state are going to create a lot more noise than up-to 385 dots.