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Informationen zum Autor Erik Larsen and Ronald M. Aarts are the authors of Audio Bandwidth Extension: Application of Psychoacoustics, Signal Processing and Loudspeaker Design, published by Wiley. Klappentext Bandwidth extension (BWE) refers to various methods that increase either the perceived or real frequency spectrum (bandwidth) of audio signals. Such frequency extension is desirable if at some point the frequency content of the audio signal has been reduced, as can happen for example during recording, transmission or reproduction. This volume, significant in dealing exclusively with BWE, discusses applications to music and speech and places particular emphasis on signal processing techniques. Presents an all-encompassing approach to BWE by covering theory, applications and algorithms Reviews important concepts in psychoacoustics, signal processing and loudspeaker theory Develops the theory and implementation of BWE applied to low-frequency sound reproduction, perceptually coded audio, speech and noise abatement Includes a BWE patent overview Audio Bandwidth Extension pulls together recent developments in to a single volume and presents a coherent framework to the reader. Such an approach will have instant appeal to engineers, specialists, researchers and postgraduate students in the fields of audio, signal processing and speech. Zusammenfassung Dealing with bandwidth extension (BWE)! this book discusses applications to music and speech and places particular emphasis on signal processing techniques. It reviews concepts in psychoacoustics! signal processing and loudspeaker theory. It also includes a BWE patent overview. Inhaltsverzeichnis Preface. I Introduction. I.1 Bandwidth Defined. I.2 Historic Overview. I.2.1 Electroacoustic Transducers. I.2.2 Sound Quality. I.3 Bandwidth Extension Framework. I.3.1 Introduction. I.3.2 The Framework. 1 From Physics to Psychophysics. 1.1 Signal Theory. 1.1.1 Linear and Non-linear Systems. 1.1.2 Continuous-time LTI (LTC) Systems. 1.1.3 Discrete-time LTI (LTD) Systems. 1.1.4 Other Properties of LTI Systems. 1.1.5 Digital Filters. 1.2 Statistics of Audio Signals. 1.2.1 Speech. 1.2.2 Music. 1.3 Loudspeakers. 1.3.1 Introduction to Acoustics. 1.3.2 Loudspeakers. 1.3.3 Bessel and Struve Functions. 1.4 Auditory Perception. 1.4.1 Physical Characteristics of the Peripheral Hearing System. 1.4.2 Non-linearity of the Basilar Membrane Response. 1.4.3 Frequency Selectivity and Auditory Filters. 1.4.4 Loudness and Masking. 1.4.5 Pitch. 1.4.6 Timbre. 1.4.7 Auditory Scene Analysis. 1.4.8 Perceptual Modelling - Auditory Image Model. 2 Psychoacoustic Bandwidth Extension for Low Frequencies. 2.1 Introduction. 2.2 Psychoacoustic Effects for Low-frequency Enhancement of Small Loudspeaker Reproduction. 2.2.1 Pitch (Harmonic Structure). 2.2.2 Timbre (Spectral Envelope). 2.2.3 Loudness (Amplitude) and Tone Duration. 2.3 Low-Frequency Psychoacoustic Bandwidth Extension Algorithms. 2.3.1 Overview. 2.3.2 Non-Linear Device. 2.3.3 Filtering. 2.3.4 Gain of Harmonics Signal. 2.4 Low-Frequency Psychoacoustic Bandwidth Extension with Frequency Tracking. 2.4.1 Non-Linear Device. 2.4.2 Frequency Tracking. 2.5 Subjective Performance of Low-Frequency Psychoacoustic Bandwidth Extension Algorithms. 2.5.1 'Virtual Bass'. 2.5.2 'Ultra Bass'. 2.6 Spectral Characteristics of Non-Linear Devices. 2.6.1 Output Spectrum of a Rectifier. 2.6.2 Output Spectrum of Integrator. 2.6.3 Output Spectra in Discrete Time. 2.6.4 Output Spectrum of Clipper. 3 Low-frequency Physical Bandwidth E...
