The Legend of Zelda: Tears of the Kingdom has plenty of content outside the main story, and here’s a guide for how to complete An Eerie Voice, which is part of the Lucky Clover Gazette side quests you do with Penn called Potential Princess Sightings!
How to Complete “An Eerie Voice” Quest in Zelda: Tears of the Kingdom (TotK)
Speak with Penn at Highland Stable in Faron, and he’ll tell you about the eerie voice that locals have been hearing at night. He says that he’ll accompany you to investigate the voice, so you need to talk to him at night to begin the quest.
I headed into the stable and purchased lodging, setting the wake-up time for night to skip waiting.
Penn is still waiting by the stable’s gate, and when you talk to him at nighttime, he’ll fly a slight distance away, entering the plains. He’s visible from where you spoke with him, so head to his location, and you’ll begin hearing the voice that’s been scaring locals.
At this point, Penn is no longer helpful. If anything, he makes the area where you can start hearing the voice. But his position does let you see the Haran Lakefront Well.
Jump into the well, and you’ll find the source of the mysterious voice, which is unsurprisingly not Princess Zelda. Additionally, if you’re low on weapons, there are plenty for you to grab at the bottom of the well!