Which type ardiuno is suitable for sond analyiz
From 31 till 12000 Hz?
I'd suggest you start with a computer. Then once you've got your concept working you'll have a better idea of what you need and what you can do. But, it seems to me that you'll probably want to connect to a computer anyway. A computer already has a soundcard, and assuming you have a laptop you've also got a microphone.
I don't have a good feel for how much processing power you need, but depending on how much resolution you need (both frequency and amplitude) you may need a computer or a specialized DSP chip. People have made some nice spectrum analyzer effects with the Arduino, but you can't build a real audio spectrum analyzer with it. A real spectrum analyzer is an expensive piece of equipment. ...It' s question of how much precision/accuracy you need.
[u]Audacity[/u] (free) can show you a spectrum so you can get started without any programming. (Audacity will only show you a spectrum of a recording, so it doesn't work in real-time, but Audacity can record.)
Or you can find spectrum analyzer applications that do work in real-time, if that's what you want.
Some people doing "serious" audio analysis use Matlab (or one of the free Matlab clones) rather than writing their own C/C++ code.
You can't run the same programs on a computer and the Arduino, but you can write C or C++ programs for either platform, and the same concepts, logic, and algorithms can be used.