YSDA Speech Processing Course

Course program

Week 1: Introduction to Speech
- Lecture: In this lecture we introduce the area of speech processing, discuss historical background and current trends. In the second half of the lecture we introduce the concept fo speech as a separate modality from text or images and foreshadow concepts from later lectures.
Week 2: Digital Signal Processing
- Lecture: In this lecture we discuss how to transform an audio signal into a form which is convenient for use in Speech Recognition and Synthesis. We discuss: how an audio wave is sampled and digitized; The Fourier Transform and the Discrete Fourier Transform and how they can be used to obtain the frequency spectrum of the signal; How to use the Short-Time-Fourier-Transform to represent sound as a Spectrogram; finally, we discuss the Mel-Scale and how to obtain a Mel-Spectrogram.
- Seminar: In part 1 we will implement the Short-Time-Fourier-Transform and obtain a Mel-Spectrogram. In part 2 we will: recover a Spectrogram from a Mel-Spectrogram. Reconstruct the original audio signal via the Griffin-Lim algorithm and do some simple voice warping.
- Homework: Audio-MNIST: Implement a Neural Network model to do simple digit classification based on a mel-spectrogram.