Plotter can't visualize correct wave and Filterbank energies

[amtommy]

After executing the stream_audio.py with the microphone, I got a result similar to the image below.

Does anyone know why this program needs to be handled like the example below?

        # Wave
        plt.plot(data[-len(data) // 2 :])

        # Filterbank energies
        plt.imshow(fbank[-fbank.shape[0] // 2 :, :].T, aspect="auto")