Stable Microphone signal

Hi all,

It has been a long time i posted a question/problem. All my project are going well so far, but now i stumple on a little problem that i dont know how to fix. What i am trying to do is capture the noice level of my car engine with a microphone, that value will be linked to the audio volume of my stereo.

I have tried it with this little microphone from ada: SparkFun Electret Microphone Breakout - BOB-12758 - SparkFun Electronics

But the the signal is not stable at all. It often goes back to zero (for a few miliseconds) and then gives the new value wich is all over the place and not really stable. Does anyone know a good way to capture audio trough the arduino in a stable way? Any good hardware you can advice me?

Thx for helping.

Thank you for your advise, i will look into it!