A strange tune is SP?

Hey everyone.
I'm not gonna waste any time so let's jump right into it. For a couple nights now I've been hearing this strange melody while in deep SP. For the first night I heard it I didn't think much of it because my house usually has a lot of noise and my parents room and mine shares a wall and they like to watch TV at night. Of course I just thought i was the TV that was making the noise, but I heard the same tune again the next night. It's sort of like a strange, mysterious tune that you might hear in a video game when entering a strange area. I noticed this only happens when I hit deep sleep paralysis. My question to you guys is; what does it mean? I'm not really close to falling asleep (even though I'm in pretty deep SP) so it can't be me actually about to 'pass out'. I was wondering what exactly does this noise apprise?

Its just similar to HI, except it is noise. I would pay attention to it and try to let it intensify until you are in a dream or able to enter a dream.