my iphone played random scary audio

While I was listening to music with headphones, I heard a small random sound play alongside my music, it sounded like out of a video game, but seeing as I was scrolling on Twitter with no video on screen I was a little weirded out. I paused my music to see if it would happen again. Nothing happened for a long time. I was scrolling through Instagram when I heard the craziest thing. It was what seemed like two people talking and a woman screaming, there was also what seemed like the sound of someone being hit. I very quickly swiped out of the post and it stopped, but because I was curious I went back to the post again and the audio began again from the beginning. This time I listened for much longer and heard the same sounds except it faded out into a static noise, and then a man started talking about a murderer, it was such an angry voice and the static got louder until eventually I just got so freaked out that I saved the post and quickly exited Instagram. Hours later I went back to the post to see if it was still happening but I couldn't hear anything. Is this just a glitch or should I be worried?

I don't go on any shady websites and have no reason to believe that my phone is hacked or has a virus. I'm just very scared and need some sort of explanation.