Is it normal this is happening

I have a bunny who isnt scared of things like never react to noises etc but today very scared. While I was away my mom said he got so terrified by something in my room he was just flying about in there and thumping.
Tonight while me and my mom were talking in my room he is as normal but all of a sudden runs up to the other side of my room, stares at nothing and then starts thumping, squeaking and running away. He kept doing this multiple times. Now he is just hopping about but he stops and listens to things all the time, lifting his ears and staring into space or looking from one side to the other while listening. I took my phone to record to see what he might be hearing and sat in complete silence with it next to my mom. When I put the recording into my laptop there were... well first of all a female voice which sounded a lot like me... The voice said what sounded like the beginning of a word before being drowned out by whitenoise again. The rest of it had... growling. It sounded like big dogs growling near the mic in two parts of the recording. And there is no explanation for it. The room was quiet, quiet outside and not even the neighbours are making any noise right now. I'm not sure if the growling were from dogs either, it was hard to hear properly through the white noise. It might also have been a man hissing and saying things in a very low voice like mumbling. Not that there's any logical explanation to that either especially since it was near the mic... But it was there. And it must be what's scaring my bunny. Should I be concerned about this? I dont think i'll be able to sleep tonight. I have recorded my room in the past several times for fun and never caught anything like this even when there's been noises around like children outside, tv on etc....So ya.