Filter Banks for Spectral Analysis and Synthesis

Abstract

In contrast to the transform-based methods of the previous chapter, in this chapter the authors discuss spectral analysis using narrowband filters. The polyphase network filter bank is a very efficient implementation of the short-term spectral analyzer and the short-term spectral synthesizer. The objective of the quadrature mirror filter approach is the spectral decomposition of the signal x(k) into M = 2 K real-valued sub-band signals with maximum sampling rate decimation as well as the reconstruction (synthesis) of the signal from the sub-band signals. The authors describe a digital filter structure for fixed or adaptive spectral modification of speech and audio signals. It is derived from a reference filter bank and is called filter bank equalizer. Main applications are audio equalization and noise reduction.

Authors 2

1. Peter Vary Aachen Institute of Communication Systems

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Institute of Communication Systems, Aachen, Germany

2. Rainer Martin

   Ruhr University Bochum

   Affiliation as printed

   Ruhr-Universität Bochum, Institute of Communication Acoustics, Bochum, Germany