How to Find Frequency while recording voice in iphone?

In my application i have done to record the voice and playing in the device. Now i want to find the audio frequency of that recorded voice(While recording). How can i find?.I d开发者_运维百科ont have any idea. I have downloaded "aurio Touch" program.But its too difficult to understand me. So is there any tutorials are avilable(in iPhone)?. How can i achieve this?

Please guide me.

Thanks.

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This involves math. If that scares you, you should probably get/buy a library to do the analysis for you. If not, Fourier transform is a good place to start to see what's involved. When I did this, I started by poking around Audacity's source code to get an idea of what's involved.