digital modeling of speech signal
DESCRIPTION
ADSPTRANSCRIPT
Digital modeling of SPEECH SIGNAL
Speech Signal:
Vocal source: Lung, vocal cord and vocal gate
Vocal tract: start from voice gate till lip including throat and air tract.
In addition to that mouth cavity, nose cavity, lip.
Digital model
Simply we can represent speech signal using the schemes PCM,DPCM,DM etc..
For example PCM technique,
Applying sampling theorem to the digital signal of speech.(if the signal band width is W hertz then the sampling period must be T<= 1/2W.)
Measure of fidelity of PCM is SNR in this noise or error signal will be
Linear Predictive Method
This is the simple method to analyze speech signal
Basic idea sample of speech is approximated as linear combination of past speech signals.
Transfer function speech samples
Let speech signal be x(n)
With linear predictor
Predictor error will be
Predictor polynomial:
Use of Linear Prediction
Spectrum estimation : If the predictor polynomial is assumed to represent the denominator of the vocal tract transfer function, we can obtain frequency response of vocal tract as
Pitch detection
Speech synthesis.
Thank You…