Help Plz - Room Noise Detector

[Birdie]

Hello...I reallyneed help
I'd like to ask some questions about the room noise detector circuit in page :
http://www.electronics-lab.com/projects/sensors/012/index.html

1- How can i try simulation for it ?? as i tried Multisim 8 but i faild to find a mic so is there anyway for simulation ???
2- Is it possible to work with a square wave signal as input instead of the mic ???
3- what's the 2 poles 4 ways rotary switch & how can it be connected ???

I'll be really glad if someone answers these questions  ???

[audioguru]

1- How can i try simulation for it ?? as i tried Multisim 8 but i faild to find a mic so is there anyway for simulation ???
2- Is it possible to work with a square wave signal as input instead of the mic ???

Look at electret mics in Google and you will learn that they produce an audio signal of from 5mV when the sounds are soft to 100mV when the sounds are loud. Your simulator has a signal generator that can be used instead of a mic.

3- what's the 2 poles 4 ways rotary switch & how can it be connected ???

It is a switch with two sections and four positions. The 1st section is at the left of the schematic to change the sensitivity of the 1st opamp. The 2nd section is at the right side of the schematic and turns on and off the power when the switch is turned.