Do you know that?

I don't think anyone else has experienced the same thing, and it sounds a bit strange, but it's worth a try, haha. I usually put something on to help me sleep, be it a TV show or rain sounds on YouTube. I've noticed for the past two days that whenever I lie down at night and close my eyes, I can't hear anything for a second, and it feels like my heart is "stopping." But as soon as I open my eyes, it's gone. I asked chatgpt, and it's supposed to be hypnagogic, which is supposed to happen when you go from being awake to sleeping. My question is, has anyone ever experienced this? It happens a few times before I finally fall asleep. I think if it were heart palpitations or extrasystoles, I wouldn't hear nothing for a second, right? Maybe someone knows something about it! Thanks 🙂