Colors of noise Puns

We're seated to a family dinner at our hotel. I'm sitting across from my sister and next to my dad. The waiter brings our meals: lamb for me, lamb for my sister and fish for my dad.

Suddenly, he lost all the color in his face. In retrospect, we're not sure how he pulled that part off, but he seemed genuinely terrified as a lead into it.

Dad: "Oh my god, did you hear that?"

Me: "Hear what?"

Sister: "What's going on?"

Dad: Listen!

Ambient restaurant noises.

Me: Dad, seriously, are you ok? What's going on?!

Dad: I can't believe you can't hear it. They must have brought you the silence of the lambs...