New here! 👋🏽 Sounds heard during meditation.

I have tried meditation on and off since losing my 10 year old son to SUDC 2 years ago. I’m doing it in the hope of connecting with him. Tonight I was in his room, noise cancelling headphones and just trying to focus on my breathing. As I relaxed I heard bird song and a sound like when you blow over a glass bottle, in different tones, on and off. I’ve only ever tried guided meditation before and end up falling asleep. I was surprised to “hear” sounds with noise cancelling headphones on in a silent room. Just wondered if this is a common phenomenon and whether it means anything? 🙏🏽🤍