Microphone Specific Signal to activate interupt [closed]

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A heads up, i am very new to audio so please bear with me =)

I am trying to interpret audio signals into an AVR (its a classical myAVR MK2 board). Now normally, the interupt signal is always some kind of switch. So if i press this swich, go into that interupt.

My goal is to interpret audio signals via microphone into the board, and have the board react to it. My first question is, when sending the microphone signal, do i have to put it through the A/D Converter, since technically it is an anolag signal ??

My second and more complicated question is, how would i actually interpret the audio signal coming in?

For example, if i scream "GREEN" then what ever the programm was doing should be stopped, the interupt should be called and the green LED should come on. Now the mic is preatty much always on ... how do i control so that only if GREEN is said, the interupt signal is sent. I dont want him constantly going in and out of the interupts just because someone made some noise ...

Would i have to save "GREEN" as a bit-combination somewhere and compare the incoming signal with the saved bits ... or ??

Answer 1

Some answers:

...do i have to put it through the A/D Converter, since technically it is an anolag signal ?  

Yes, digital chips may fry when exposed to analog signals.
Be aware that you may have delay some time after starting the ADC before the signals are accurate.

how would i actually interpret the audio signal coming in?  

Basically you have digital values coming in at a frequency. You will need to store those values and then analyze them. You must trade memory capacity/usage for accuracy. The more samples you take, the better your data and results; but this occupies more memory.

You will also need to filter out noise from the signal and from layered sounds.

You may get some benefits from researching on FFTs.

You should compare using "fuzzy logic" because in the real world, nothing is exact; for example your voice signal could be +/- 30 counts and still be "correct".