Greetings Whoayeah,
Thank you for bringing this issue to our attention. We'll forward this suggestion to the devs to see if we can make the content more accessible to all of our Adventurers.
As cool and immersive of an idea it is to require hearing to find the Hollow Maretta, there are deaf/hearing impaired people who play this game and need reasonable accessibility features to enjoy the game and new content like everyone else.
I have a long time Guild member and personal friend that is completely deaf. She was saying some kind of visual cue would be greatly appreciated as she has no idea when the Siren spawns. There is zero reason why anyone shoudl down vote a small visual cue for deaf players unless they are griefing the forums. This is a disability issue.