Am I Imagining Things?

PS5 user here. I've been starting to use the Serpent gadget more, and have come across a strange phenomenon; when I activate it, I notice my controller will vibrate in one of 2/3 ways, and if I hold it close to my ear I SWEAR the vibration sounds like Kiryu saying 'kakugo ika' or 'ikuze!'. My controller speaker works just fine, and I would think the line would be coming out of there. Am I insane? Has anyone else come across this?