JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Advanced Digital Signal Processing

Course Objectives

The objectives of this course are to make the student

• Understand the anatomy and Physiology of Speech Production system
• To analyze the speech in time domain and extract various time domain parameters
• To study various Speech Signal Processing applications viz: Speech Enhancement, Speech Recognition, Speaker Recognition.
• To study various Audio coding techniques based on perceptual modeling of the human ear.

Course Outcomes

On completion of this course student will be able to

• Model an electrical equivalent of Speech Production system.
• Extract the LPC coefficients that can be used to Synthesize or compress the speech.
• Design a Homomorphic Vocoder for coding and decoding of speech.
• Understand the concepts of Speech and Speaker Recognition systems.
• Design basic audio coding methods for audio signal.

UNIT - I

Fundamentals of Digital Speech Processing: Anatomy & Physiology of Speech Organs, The Process of Speech Production, The Acoustic theory of speech production- Uniform lossless tube model, effect of losses in vocal tract, effect of radiation at lips, Digital models for speech signals. Perception: Anatomical pathways from the Ear to the Perception of Sound, The Peripheral Auditory system, Hair Cell and Auditory Nerve Functions, Properties of the Auditory Nerve. Block schematics of the Peripheral Auditory system.

UNIT - II

Time Domain models for Speech Processing: Introduction – Window considerations, Short time energy, average magnitude, average zero crossing rate, Speech vs Silence discrimination using energy and zero crossing, pitch period estimation using a parallel processing approach, the short time autocorrelation function, average magnitude difference function, pitch period estimation using the autocorrelation function. Linear Predictive Coding (LPC) Analysis: Basic principles of Linear Predictive Analysis: The Autocorrelation Method, The Covariance method, Solution of LPC Equations: Cholesky Decomposition Solution for Covariance Method, Durbin’s Recursive Solution for the Autocorrelation Equations, comparison between the methods of solution of the LPC Analysis Equations, Applications of LPC Parameters: Pitch Detection using LPC Parameters, Formant Analysis using LPC Parameters.

UNIT - III

Homomorphic Speech Processing: Introduction, Homomorphic Systems for Convolution: Properties of the Complex Cepstrum, Computational Considerations, The Complex Cepstrum of Speech, Pitch Detection, Formant Estimation, The Homomorphic Vocoder. Speech Enhancement: Speech enhancement techniques: Single Microphone Approach, Spectral Subtraction, Enhancement by re-synthesis, Comb filter, Wiener filter, Multi Microphone Approach.

R19 M.TECH. SYSTEMS AND SIGNAL PROCESSING

UNIT - IV

Automatic Speech Recognition: Basic pattern recognition approaches, parametric representation of Speech, Evaluating the similarity of Speech patterns, Isolated digit Recognition System, Continuous word Recognition system. Elements of HMM, Training & Testing of Speech using HMM. Automatic Speaker Recognition: Recognition techniques, Features that distinguish speakers, MFCC, delta MFCC, Speaker Recognition Systems: Speaker Verification System, Speaker Identification System, Performance Metrics.

UNIT - V

Audio Coding: Lossless Audio Coding, Lossy Audio coding, Psychoacoustics, ISO-MPEG-1 Audio coding, MPEG - 2 Audio coding, MPEG - 2 Advanced Audio Coding, MPEG - 4 Audio Coding.

TEXT BOOKS:

• 1. Digital Processing of Speech Signals - L. R. Rabiner and S. W. Schafer. Pearson Education.
• 2. Digital Audio Signal Processing – Udo Zolzer, 2nd Edition, Wiley. REFERNCES:
• 1. Discrete Time Speech Signal Processing: Principles and Practice - Thomas F. Quateri, 1st Ed., PE.
• 2. Digital Processing of Speech Signals. L. R Rabinar and R W Jhaung, PHI, 1978.
• 3. Speech Communications: Human & Machine - Douglas O'Shaughnessy, 2nd Ed., EEE Press.
• 4. Speech & Audio Signal Processing- Ben Gold & Nelson Morgan, 1st Ed., Wiley R19 M.TECH. SYSTEMS AND SIGNAL PROCESSING M.TECH.- I YEAR- II SEMESTER SYSTEMS AND SIGNAL PROCESSING