During Singularity expedition, we are tasked with forging the Seed of Will, which is "unsuppressable will to exist" taken physical form. When we interact/Resonate with it, it sounds like typical Atlas Interface… except it suddenly starts to sound like an alarm, very melodic one at that.

Now for those who don't know, No Man's Sky universe is essentially a simulation run by Atlas. Atlas is the name of the supercomputer who was designed to run these simulations by some unknown race of beings. However, these beings have fled the world which was slowly being eaten by the black hole and left Atlas behind, probably too monumental in its size to be transported easily. This has caused Atlas to develop abandonment issues, depression and existential dread. According to his calculations, he has 16 of something of operational time left (this is why you see number 16 being repeated everywhere throughout the game). Also fun fact – canonically your character is the last iteration of Traveller beings, which were made out of brainscans of Atlas' creators. It creates Travellers in an attempt to find out why was he abandoned.

Now this is my theory, that the sound we hear while resonating with the Seed of Will is actually what Atlas hears in its room or other chamber where its physical body resides in. The melodic tunes we hear might be an emergency alarm sound as the physical world is slowly being torn apart by the black hole with Atlas being able to do nothing as he dies. The fact that the Seed of Will is described as "unsuppressable will to exist" could mean that Atlas wants to survive in whatever way it can. This also ties into another theory that the Construct we are assembling is actually body of the Atlas itself, which wants to traverse the simulation rather than just simulating it. I believe that this might be actually the way for Atlas to depart on its own terms – to wander around the world he has created rather than feel his body being torn to shreds in complete solitude.