The tick-tick sound comes from the movement of gears and parts inside the clock. In mechanical clocks, a part called the escapement mechanism controls this sound.

This gadget fixed my circadian rhythm.

Don’t try to force yourself into being a morning person. Trick yourself into it instead with a sunrise alarm clock.

I used to be able to hear 3kHz easily but as my hair cells fade into the sunset that frequency now seems to be down 3 or 6 dB. As a consequence the high pitched "beep beep" sound on my portable alarm ...