Ch5-Analysis_&_Synthesis_of_Pole-Zero_Speech_Models

Ch5-Analysis_&_Synthesis_of_Pole-Zero_Speech_Models...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Speech Processing Analysis and Synthesis of Pole- Zero Speech Models 2/13/12 Veton Kpuska 2 Introduction u Deterministic: n Speech Sounds with periodic or impulse sources u Stochastic: n Speech Sounds with noise sources u Goal is to derive vocal tract model of each class of sound source. u It will be shown that solution equations for the two classes are similar in structure. u Solution approach is referred to as linear prediction analysis . n Linear prediction analysis leads to a method of speech synthesis based on the all-pole model. u Note that all-pole model is intimately associated with the concatenated lossless tube model of previous chapter (i.e., Chapter 4). 2/13/12 Veton Kpuska 3 All-Pole Modeling of Deterministic Signals u Consider a vocal tract transfer function during voiced source: T=pitch U g[n] A Glottal Model G( z ) Vocal Track Model V( z ) Radiation Model R( z ) s [n] Speech ( 29 ( 29 ( 29 ( 29 ( 29 =-- = = P k k k z a A z H z R z V z AG z H 1 1 2/13/12 Veton Kpuska 4 All-Pole Modeling of Deterministic Signals u What about the fact that R(z) is a zero model? u A single zero function can be expressed as a infinite set of poles. Note: u From the above expression one can derive: ( 29 z a az az z a az k k k k k < <- = =- =-- =- 1 , 1 1 1 1 1 ( 29 a z z-b z a az k k k k k = =- =- =-- 1 1 1 1 poles of number infinite 1 zero simple 1 2/13/12 Veton Kpuska 5 All-Pole Modeling of Deterministic Signals u In practice infinite number of poles are approximated with a finite site of poles since akfi 0 as kfi . u H(z) can be considered all-pole representation: n representing a zero with large number of poles inefficient n Estimating zeros directly a more efficient approach (covered later in this chapter). 2/13/12 Veton Kpuska 6 Model Estimation u Goal - Estimate : n filter coefficients {a1, a2, ,ap}; for a particular order p, and n A, Over a short time span of speech signal (typically 20 ms) for which the signal is considered quasi-stationary. u Use linear prediction method: n Each speech sample is approximated as a linear combination of past speech samples n Set of analysis techniques for estimating parameters of the all-pole model. 2/13/12 Veton Kpuska 7 Model Estimation u Consider z-transform of the vocal tract model: u Which can be transformed into: u In time domain it can be written as: u Referred to us as a autoregressive (AR) model....
View Full Document

Page1 / 82

Ch5-Analysis_&_Synthesis_of_Pole-Zero_Speech_Models...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online