Why an electronic cricket? Many people like the cricket sound specially if they live in a big town. This electronic cricket circuit works in pulses, so the battery life is prolonged, the current consumption is just 2mA.
Schematic of the electronic cricket circuit
Electronic cricket simulator pcb
The electronic cricket schematic is very simple, it is build with CD4049 or CD4009 wich is CMOS Hex Buffers/Converter.