I coach many people on how to be heard from the way they sit or stand, to their word choice, intonation, and delivery. All of those matter but none so much as your willingness to speak. You have to make your presence and opinion known. Don’t minimize the contribution and impact you can have by silencing yourself. I know, we have that internal conversation, “they won’t listen to me anyway so why bother?”.
Your voice matters. Your voice has an impact even when you are unaware of the impact. People are listening.