The annoying beat of your heart as felt through you ears on your pillow at night when you are trying to get to sleep.
For the paranoid amongst us - the ear beat can be the difference between a healthy night's sleep, or a night of panic induced "shit, that doesn't sound right" ery!!
It is also very easy to get entranced by the whole "ear beat" and those musically minded people may start playing beat games which will ultimately only ever lead to the worst of all things when trying to go to sleep - an active mind and a guaranteed crap nights sleep
annoyed female in morning: Get out of bed you lazy sod
man: Sorry, awake all night listening to the ear beats
Hey Pete, I just couldn't get enough of those ear beats last night but man am i now tired!!