Can FFT be used to find peaks and pits on audio files I'm able to read wav files and its values. I need to find peaks and pits positions and their values. 

First time, I tried to smooth it by $\frac{(i-1 + i + i + 1)}{3} $
formula, then searching on array as array[i-1] &gt; array[i] &amp; direction == 'up' --> pits style solution. But because of noise and other reasons of future calculations of project, I'm trying to find a better working area. 

Since couple days, I'm researching FFT. As my understanding, FFT translates the audio files to series of sines and cosines. After FFT operation the given values is a0's and a1's for $a_0 + a_k * cos(k*x) + b_k * sin(k*x)$ which k++ and x++ as this picture:



My question is, does FFT helps to me find peaks and pits on audio? Does anybody has a experience for this kind of problems?
FFT is a tool to look at your signal content in frequency domain. So if you want to find peaks of your time domain signal, FFT cannot help you. However if you want to see what frequency component in the signal is the largest then you can use FFT.
To find peaks of your time domain signal you can load it into MATLAB and use command "max" for example if your signal is called "mySignal" in MATLAB type: max(mySignal) and it will give you the location of value of the peak.