Imaginary sounds.

Have you ever heard your phone ring and run to pick it up, only to realise it was all a figment of your imagination?

Or felt a vibration in your pockets or in your bag and rush to get it out, and again only to realise it wasn't real?

Or heard the all-too-familiar degedeng sound of the receival of an instant message even when you're in the kitchen and your computer is far off in a different part of the house?

I have no explanation as to how they happen. I only tell myself it's because I keep hearing it, so its registered in my memory, then it replays itself, like how some words keep ringing in your ears.

Hey, if you've got a more valid scientific explanation, do enlighten me.