Electronic Metronome Generates Mechanical Sound

This is a metronome circuit that has mechanical sound character. The metronome that has mechanical sound character will make our life more fun and it would be elegant and cool. Here is the circuit :
electronic-metronome-with-mechanical-sound
This circuit uses two two 555 oscillators. To make high frequency tone, it uses first oscillator and to produce the beat timing this circuit uses second oscillator.