Pre-processing Steps for Speech Signal Processing

The pre-processing phase of speech signal processing, comprising steps like pre-emphasis, framing, and windowing, provides an excellent introductory reference for learning speech signal processing. During pre-processing, the initial step involves pre-emphasis to enhance high-frequency energy components, typically implemented using a first-order FIR filter like y(n) = x(n) - αx(n-1) where α ranges from 0.95 to 0.97. The speech signal is then segmented into multiple frames, each containing a fixed number of sampling points (commonly 256 or 512 samples per frame), with optional overlapping between consecutive frames. Subsequently, windowing functions (such as Hamming or Hanning windows) are applied to each frame to reduce discontinuities at frame boundaries, implemented through point-wise multiplication between the frame data and window coefficients. This pre-processing program offers beginners comprehensive guidance to deeply understand fundamental concepts and procedural steps in speech signal processing.