An open source Noise-Vocoder for pitch degradation.

Algorithm steps :

1. Input Parameters:

   • ‘x’: input signal

2. Envelope extraction:

   • envelope = abs(x)

3. Low-Pass Filtering:

   • Smooth the envelope by removing high-frequency components, leaving only the slower amplitude variations.

4. Filtering the input signal and the noise

• Generates white noise with the same length as the input signal.
• Applies a filter bank to both the input signal x and the generated noise.

5. Modulating the input signal bands with the noise bands

6. Multiplying with the extracted envelope

• Multiplies the envelope with the corresponding frequency band of the filtered noise. (Modulates the noise with the amplitude variations of the input signal)

7. Summing the modulated bands

• The modulated bands are summed up across all frequency bands.