Signal Processing Through Filters with Time-Frequency Domain Analysis of Output Signals

In this workflow, we first acquire a monaural audio signal in .wav format and perform sampling using the WAVREAD function for data input. We then conduct spectral analysis on the audio signal and design three types of digital filters: low-pass, high-pass, and band-pass. For FIR filter implementation, we employ the windowing method (using functions like hamming or hanning) to control frequency response characteristics. For IIR filter design, we apply the bilinear transform method (utilizing functions such as butter or cheby1) to convert analog prototypes to digital filters while preserving stability. Subsequently, we develop M-file scripts to process the input signal through these designed filters. The analysis phase includes examining output signals in both time-domain (using plot and stem functions for waveform visualization) and frequency-domain (employing FFT and spectrum analysis tools for magnitude/phase response evaluation), providing comprehensive insights into filter performance and signal transformation characteristics.