Robustness Techniques for Feature Extraction - Berlin Chen

Vector Taylor Series (VTS) P. J. Moreno,1995
• A Model-based Noise Compensation Technique
• VTS Approach
– Similar to PMC, the noisy-speech-like models is generated by
combining of clean speech HMM’s and the noise HMM
– Unlike PMC, the VTS approach combines the parameters of
clean speech HMM’s and the noise HMM linearly in the logspectral
domain
P ω = P ω P ω + P ω
Power spectrum
X
X
( )
S
( )
H
( )
N
( )
= log( PS
( ω) PH
( ω) + PN
( ω)
)
⎛ ⎛ P
( ) ( )
( ) ⎞
⎜
N
ω ⎞
= log PS
ω PH
ω ⎜
⎟⎟
1 +
PS
( ) PH
( )
⎝ ⎝ ω ω ⎠⎠
logPN
( ω) −logPS
( ω) −logPH
( ω)
= logP
( ω) + logP
( ω) + log1+
e
l
= S
= S
l
l
S
+ H
+ H
l
l
+
f
H
Log Power spectrum
( )
( )
N −S
−H
+ e
Non-linear function
( ) ( ) ( )
l l l
l l l
N −S
−H
S , H , N , wheref
S , H , N = log1+
e
+ log1
l
l
l
l
l
l
Is a vector
function
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