A very simple electronic circuit that imitates sound of a cricket can be achieved using this electronic scheme. The circuit contains four oscillators, the first, N1, take note of the acute. The frequency of this note is fixed with potentiometer P1, so that it is in the range of a resonant piezo buzzer: the sound is therefore stronger.
To get the sound of a cricket, 4 kHz rectangular output of N1 is modulated in amplitude with a frequency of 10 ... 20 Hz, produced by N2 oscillator frequency shift and how numeric N4.
To make the final result to be as real "cricket" sound should not be continuous, it must have some breaks. This is done with the oscillator N7 / N8 and N6 frequency shift.
Initial adjustment of the circuit is done with P1 to obtain basic sound. For the buzzer to be connected directly to the gate N1 output (pin 3 of IC1's). Buzzer is then connected to pin 11 of IC1 and P2's adjustable to obtain a typical cricket sound. Then connect the buzzer to pin 3 of IC1 and adjust P3's so noise to be heard by 3 or 6 times per second.