I said yes, but it wasn't my partner. It was me!
When my husband and I met, I was ridiculously open with him. I even went so far as to let him know that I have a rather high libido, and I will go searching for sex elsewhere if he can't keep up. Not cheating, mind, but an open relationship.
Then, when we got down to it, I was way too embarrassed to express my pleasure vocally.
One day, M (hubby) said to me, "I can't tell if you actually like sex with me, or if you just endure it because you want to be with me on an emotional level."
So we talked about it, and I promised to give being vocal a try. And I liked it! Imagine that.
Talk to your partner. Maybe it's just not their thing. If that's the case, there are other ways of knowing your partner's into it.