Eight out of twenty four

Hardly a pass mark, is it? Only 33%. But if you score 33% for sleeping, you are top of the class and fortunate indeed.

Research has shown that people generally like to sleep between five and eleven hours in every twenty four, the average preferred period being just under eight hours. No-one really knows why we sleep, but it is absolutely essential to our health, as necessary as air, food and water. Adequate sleep is necessary for proper brain function - thinking, evaluating, memory, coherent speech, concentration. Lack of sleep effects every part of life - jobs, relationships, productivity and safety.

Staying awake for only seventeen hours at a stretch - which many of us do every day - leads to a decrease in performance similar to that experienced by drinking two glasses of wine!

Quality sleep needs to be continous and uninterrupted. And here-in lies a problem. Most of us live in densely populated areas. All our neighbours have at least one dog and one car. And probably an alarm system. We all live in close proximity to main roads. Not to mention small children who have bad dreams or wake for feeding.

We can habituate to certain noises or sounds - this means that the sound is so consistent that you stop noticing it - the clock ticking, the thrumming of electrical appliances, that sort of thing - but a sudden loud noise, or a change in the quality of a sound, or even a cessation of a noise can wake us. Then we have to start going through the various sleep stages again, from the beginning, until we get back to deep beneficial sleep.

There is little we can do to combat night noise polution. Some people go to bed wearing earplugs, but personally I've found that physically uncomfortable, and I feel very vulnerable when I can't hear. Others use an air-conditioner to give an overlay of 'white-noise'. I guess it's a case of whatever gets you through the night.