Wake-One- Only Alarm Clock

In a dorm, most rooms are shared, which is often the same situation for husband and wife, brothers and sisters, etc. The reality is most people have different schedules, and therefore they have different times they need/desire to wake up. 

However, most alarm clocks will wake all the people up in the room creating quite some disturbance. I wonder whether it is possible to make a new device or develop a new solution to these situations.

WYS General Education
This idea was come up by Sebastien Yang. Through discussion with Professor Bernard, we understood there is currently a market solution for this idea. The attached image is from an online source, http://en.wikipedia.org/wiki/Alarm_clock