If I were you I would ask a doctor about it. Like stijn (and others) said, it could be something incredibly serious. We aren't doctors, but we also know that that might be a more probable cause than paranormal spirits... ^_^; Having said this, it could just be lack of sleep or whatever, but even if you think it might not be, don't put it off and hope it will go away. If you do and it doesn't, then you could be in trouble.

it could be stress related, just thinking about it because if you have alot of issues going around they can build up in to some thing more serious, just don't worry about it and go to see a doctor about it.

You need to go to the doctor, that can be very serious.

EDIT:: Typing error. lol.

I don't blame FloralFairy at ALL for at first thinking paranormal. It's what I did. Now, having said that, I've been hearing and seeing things for a while now, and that's not my brain, or any psychological disorder, because I'm quite fine.

I agree with what was said about the "echos" though. When I go to bed, the TV is always on downstairs, because my parents stay up much later than I do. And sometimes, if I am staying up later and they have both gone to bed, I can hear the TV as clearly as if they were actually downstairs watching it, despite the fact that it is quite obviously turned off.

And so, I ask you this, Are you wide awake when you hear this, or is it as you are going to sleep or whatever?

The reason I ask is that there is a transitionary period between sleep and awakeness, where the mind is more susceptible to the imagination. It's this kind of half-sleep where you feel as though you're tipping backwards, yet you know you're lying flat, (I love it when this happens, it sets my adrenaline off. ^^; ). I have, on occasion, heard things which have woken me into a full state of awareness, but because I was semi-aware, I thought I actually heard it.

Then there was the time my kitchen ceiling caved in and the bath dropped through the roof, which actually WASN'T a dream.. But I digress.