Signal spectral analysis:
Given the four practical signals below, compute their one-sided spectra and create their time domain plots and spectral plots, respectively:
a. Speech signal ("speech.dat"), sampling rate = 8,000 Hz. From the spectral plot, identify the first 5 formants.
b. ECG signal ("ecg.dat"), sampling rate =500 Hz. From the spectral plot, identify the 60 Hz-interference component.
c. Seismic data ("seismic.dat"), sampling rate =15 Hz. From the spectral plot, determine the dominant frequency component.
d. Vibration signal of the acceleration response from a simple supported beam ("vbrdata.dat"), sampling rate = 1,000 Hz. From the spectral plot, determine four dominant frequencies (modes).