The time required for the power supply battery (Mignon) is commendably included.
Despite non-existent second hand of the clock is not completely silent, because the minute hand every 15 seconds by a quarter minute advances and thereby makes a slight noise excessive. This sounds like a grain of rice, which on a sheet of paper falls from height egringer. Due to the large time interval, it does not interfere with (me).
The alarm signal (beep-beep-beep -! Beep-beep-beep) starts relatively quietly and after a few seconds a little louder. For people with normal hearing, it may be impossible to go back to sleep with this noise.
I would buy the alarm clock again - it reliably fulfills its duties and for the very reasonable price of 9.40 euros (as of 11.2.2009).