Digital Signal Processing Reference
In-Depth Information
where
is the mathematical result of traditional spectral subtraction,
is the result after flooring,
determines the intensity of the
spectral subtraction, and
the flooring factor. Suitable values for
are 1.5
... 2.2. It is also possible to have an adaptive behavior of
for the
entire frequency band or in subbands (SNR,
f
) [4].
After subtraction, flooring is applied. Flooring is needed to avoid musical
tones but also to have a sensible level of comfort noise. Experiments to find
the optimal value for the flooring factor resulted in can also be
determined in an adaptive way as a function of SNR or by a different setting
for subbands.
Figure 12-5. .
Combination of VAD approaches in the time and frequency domain lead to
improved word detection accuracy
