How do you know that you have been heard?
How does it feel when you know that you have truly been listened to and really heard?
And when was the last time that you felt or knew that you had been heard?
A common (and welcome) bit of feedback from the people I work with is that they feel coaching is a safe space to talk and to be heard, and that having someone a bit outside of the immediate situation who is willing to listen is important. What someone means by being heard is likely to differ from person to person.
As a coach my job is definitely to listen and hear more than to talk (especially in a first coaching session), but it’s to listen in a particular way. Have you ever thought about how you listen? Stephen Covey discusses 5 levels of listening:

As a coach, I try to be in levels 4 and 5, but I know when I am listening in other contexts (e.g. occasionally to my children and in the ancient past in some meetings), I am guilty of being more at level 2 or 3. At level 5 we try to listen to words, voice tone, pace, pitch, tone, body movement, breathing, facial movements that are out of the ordinary for the person to whom we are listening. And I think these things might be what we listen for too in order to know that we’ve been heard. Certainly some verbal validation but also nodding, changes in body position, facial expression etc comes into it for me.
So perhaps there are also 5 levels of being heard? I need to think about that. If you’re interested in this too, perhaps practice noticing how you are listening to people.