Lot of things, like whispers from behind the Veil.
In the walls.
Harry hears his mother (Lily Potter) screaming his name.
He heard them say that Sirius Black had betrayed his (Harry Potter's) parents, resulting in their death.
Probably. We never hear anything to the contrary, at least.
harry potter aww man no SSDD
Mandrakes are a plant that helps restore those who have been petrified to their original state. Their cry is also fatal to those who hear it. Mandrakes were first introduced in the book Harry Potter and the Chamber of Secrets, and then are mentioned briefly in Harry Potter and the Deathly Hallows.
Harry Potter and the Philosopher's Stone is written in limited third person narration. We follow the story through Harry's eyes and hear what he thinks and feels. In the first chapter, we follow Vernon Dursley and Albus Dumbledore instead of Harry.
The most likely cause is that somebody tells you that it's fun to read - or that you hear about it and get curious.
I can't hear you through the computer, no. I assume that if you can type this question, you are most likely very much alive. (Unless you are Lord Voldemort, in which case I will call Harry Potter.)
By creature do you mean Horcrux? If so, it's because he is a Horcrux. Although, this didn't happen in the book.
He disappears off into the sunset.The last we hear about him is the song at the Phoenix song at Dumbledore's Funeral.
In concert halls all around the world. His bagatelle in A Minor (Fur Elise) was even heard in Harry Potter and the Deathly Hallows.