Speech Processing - December 2016

MU Electronics and Telecom Engineering (Semester 8)

Total marks: --
Total time: -- INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary 1(a) Explain in detail the human hearing mechanism with suitable diagrams. 5 marks

1(b) Explain the procedure for computation of pitch and formants based on cepstral analysis of speech. 5 marks

1(c) State and explain the applications of LPC to speech processing. 5 marks

1(d) Draw the block schematic for a text-to- speech synthesis system and explain the functions of each block. 5 marks

2(a) Explain linear filtering interpretation of short-time spectrum analysis with suitable block diagram. 5 marks

2(b) With a neat block diagram, explain non-linear smoother for estimation of parameters in speech processing. Justify the need for delays in non-linear smoother. 5 marks

2(c) Explain general discrete-time model for speech production. 5 marks

3(a) With related equations explain the terms i) Short-time energy
ii) Short-time average magnitude and iii) Short-time zero crossing rate. How do you distinguish voiced and unvoiced segments based on these parameters? 5 marks

3(b) Explain pitch estimation based of FFT analysis of speech signaL. 5 marks

3(c) Write a note on production of semivowels and nasals. Give the reason of broadening of nasal reasonances. 5 marks

4(a) Draw a diagram of single-stage lattice and write the eqautions for the lattice. 5 marks

4(b) Explain the convariance method for LPC analysis. 5 marks

4(c) What is CELP? How is the code book generated for CELP? What are the limitations of CELP? What are the modifications suggested in the basic CELP coder? 5 marks

5(a) How will you convert power spectrum to mel scale? Explain the procedure for calculations of MFCC with a block schematic. Clearly explain how the integration of poweris done on mel scale filters. How will you compress the amplitude of the power spectrum? How is spectral smoothing done? 5 marks

5(b) Write a detailed note on place and manner of articulation. 5 marks

6(a) Explain the terms "liftering" and "quefrency" in connection with cepstral analysis of speech signal. 5 marks

6(b) What is HMM? What is hidden in it? Draw a state diagram for HMM as general case and show how you can write a transition for HMM as a general case and show how you can write a transition matrix. 5 marks

6(c) Explain speech synthesis using phone-based synthesizer. 5 marks