Experiment 2 uses MATLAB toolbox to filter the audio signal with mixed noise
1. Noise addition and denoising processing of violin audio
Requirements: Select the audio signal in sub-task 1, give the system function of the filter by yourself, use two methods of time-domain linear convolution and difference equation to filter the audio signal, and compare the waveform of the signal before and after filtering and the effect of playback .
The final overall effect is as follows:
1. Construction of audio signal
① Generation of music signal:
Adobe Audition is used to extract the audio signal of a note of a violin music, as shown in the figure below: the
upper and lower signal waveforms are the left and right channels respectively. How to judge the signal as a note? Judging by the spectrum analysis of Adobe Audition , the spectrogram is shown in the figure below: The spectrogram
combines the spectrum and time of the signal, the horizontal axis is time, the vertical axis is frequency, and the depth of the color represents the amplitude of the signal. through a tone