1) Add Recording Feature: (a) Click anywhere on the screen to start recording. Click anywhere one more time to stop recording. (b) Two audio wav files are created. audioFFT.wav records the raw data which is used for analysis. audioWave.wav records the raw data which is used for displaying audio wave. 
2) FFT and Cepstrum result is almost same as the Matlab result. The different between them should not greater than 0.001.
See the NSLog for details.