Run the code, enter the duration till which you want to record(n). After start speaking is displayed, speak 1-10 (or till any limit you want) with some pauses. After the voice has been recorded for ‘n’ seconds, your audio playback will start and a graph depicting your audio will be plotted. After the playback is completed, the new audio signal with pause removed will be plotted and the playback will start (without silence).

The code already contains a noisy cosine signal with noise added through Gaussian Noise. (5 White Gaussian Noise in code). The noise can be changed in the equation “x = awgn(y,5,'measured')”. First subplot of figure 1 depicts the noisy signal and the 2nd subplot depicts the noise removed signal. X_mags computes the magnitude spectrum of the signal or otherwise the absolute Fourier transform of the signal. Now, figure 2 is generated which depicts the normalized frequencies of the DFT (Discrete Fourier Transform) plotted against the magnitude. This helps us to determine the cut-off frequency for our Butterworth Filter i.e. the value of Wn. Since it’s a 20th order filter, so n=20. Using the filter command subplot 2 of figure 1 is generated which is the noise removed signal or wave.