Rasta filtering
In today's world, Rasta filtering is a topic that has captured the attention of millions of people around the world. With its many facets and its relevance in contemporary society, Rasta filtering has become a constant point of discussion in different areas, from politics to entertainment. In this article, we will explore the different aspects of Rasta filtering, analyzing its impact on people's daily lives and its influence on popular culture. In addition, we will closely examine the latest advances and developments related to Rasta filtering, in order to offer a comprehensive view of this very significant topic in the current landscape.
RASTA filtering and mean subtraction was introduced to support perceptual linear prediction (PLP) preprocessing. It uses bandpass filtering in the log spectral domain. Rasta filtering then removes slow channel variations. It has also been applied to cepstrum feature-based preprocessing with both log spectral and cepstral domain filtering.
In general a RASTA filter is defined by
The numerator is a regression filter with N being the order (must be odd) and the denominator is an integrator with time decay. The pole controls the lower limit of frequency and is normally around 0.9. RASTA-filtering can be changed to use mean subtraction, implementing a moving average filter. Filtering is normally performed in the cepstral domain. The mean becomes the long term cepstrum and is typically computed on the speech part for each separate utterance. A silence is necessary to detect each utterance.