Why cell phones snooze buttons only give you nine more minutes?

When you use your cell phone alarm clock function, you will come across this circumstance when you press down the snooze button; it gives you nine more minutes of sleeping time. Did you ever wonder why it is nine minutes and not more or not lesser?

The reason was because it was standardized way back in the 1950′s. At that time, the teeth of the snooze gear need to be fixed, so engineers need to come out a final decision on how many minutes should it be. Once fixed, then that was it, nor any programmers or users able to make any changes on it. From studies, it shown that for human the avearage will get back into deeper sleep after 10 minutes. Therefore, if the snooze only come in after ten minutes, it could be very difficult to wake those sleepers up again.

Apparently, few decades later, our digital clocks and cell phones do not any more bound by the teeth on snooze gear. But any way, that is the standard with a reasonable support behind of it.