Getting listened to isn't really about how loudly or often you speak, it's about what happens the last several times you spoke. People give their full attention based on a track record, built well before the moment you actually need it.
The two biggest levers, in practice, are signal-to-noise ratio and follow-through. Someone who speaks up constantly, on every topic, regardless of how relevant it is, gets tuned out over time, not because any one comment was bad, but because the room can no longer tell which of their comments are worth full attention. Someone who speaks up selectively, and is reliably right or useful when they do, gets a very different kind of attention: people lean in, because experience has taught them it's usually worth it.
People don't listen harder to whoever talks the most. They listen harder to whoever has been worth listening to.
Follow-through matters just as much. If you say something will happen and it does, reliably, your word starts to carry weight before you've even finished the sentence, people have learned your statements are predictive, not just aspirational. If your stated intentions and your actual behavior have drifted apart, even good ideas get discounted, because the room has learned not to take your statements at face value.
Two people raise the same concern in a planning meeting. One has a pattern of flagging risks that reliably turn out to matter. The other flags concerns often, and most turn out to be minor. The room's reaction to the identical sentence, "I'm worried this timeline is too aggressive", is completely different, because the reaction isn't really to the sentence. It's to the track record behind it.
Delivery matters too, but less than most people assume. Confidence, brevity, and directness help a message land, see the piece on why delivery can matter more than the idea, but they amplify an existing reputation more than they create one from scratch. A brilliant, confidently delivered point from someone with no track record still gets less weight than a plainly stated one from someone the room already trusts.
If you're not yet being listened to the way you'd like, the fastest lever usually isn't speaking up more, it's being more selective about when you do, and making sure every time you do, it holds up. A handful of well-chosen, reliably accurate contributions build more listening power over a few months than a much larger volume of average ones ever will.