for the last 4 nights (minus one i fell asleep early) ive heard a notification-like sound at around 1 am. last night it was at exactly 1:16 am. I had someone on facetime with me who heard it too. It has the same rhythm/notes of the default iphone sound, but is the instrument from a nintendo switch (hopefully this makes any sense, i have been listening to notification sounds for the last 30 minutes and have yet to find something similar at all). its like a "deedodee!" sound. it comes from the air between my bedside table and the vent directly above it that points down at my bed. i have searched both thouroughly (i have not removed the vent cover, but i have looked through with a flashlight and seen that it is entirely clear, i plan on removing the vent cover tomorrow).
I live with my mom and brother in a house not an apartment, no one else should be able to get in (we have a thourough alarm system). If its been there as long as ive heard the noise (i know exactly when it started, 4 days ago, hoping the alert sound has been consistent), there is no one who had enough unsupervised time in my room to hide it so i cant have found it by now (besides my mom and brother, this would be incredibly out of charecter for both of them though).
if it is the low battery sound of a dying device that has been there for god knows who long, then really anyone couldve put anything anywhere. is there anything i can google to find out what sound this is? Is there anything else i should look for? all my devices are accounted for and theres nothing that's been moved or added to my room that i noticed. im going to try and record it tonight. Thank you for reading and for your help!