Bandwidth Extension Algorithms for Audio Quality Enhancement in Portable Audio Devices

Bandwidth Extension Algorithms for Audio Quality Enhancement in Portable Audio Devices PDF Author: Arun Thirugnanasambandam
Publisher:
ISBN:
Category : Digital music players
Languages : en
Pages : 0

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Book Description
Low bitrate audio coding is an enabling technology for a number of applications such as digital radio, Internet streaming and mobile multimedia applications. Using perceptual codecs at low bitrates however has disadvantages. Below 128 kbps, the perceived audio quality deteriorates significantly because of the limited bandwidth and often creates annoying artifacts. Spectral Band Replication (SBR) is a technique that significantly improves the compression efficiency of perceptual audio codecs and the quality of audio, by reconstructing the high frequency components of an audio signal on the decoder side. The missing fundamental is a phenomenon exhibited by a sound when the overtones suggest a fundamental frequency but the sound lacks a component at the fundamental frequency itself. This concept could be used to create a low frequency pitch perception in small speakers, which do not actually have the capabilities to reproduce such low frequencies. This thesis is an attempt to combine these two techniques (SBR and missing fundamental) to improve the quality of audio in portable audio devices.

Bandwidth Extension Algorithms for Audio Quality Enhancement in Portable Audio Devices

Bandwidth Extension Algorithms for Audio Quality Enhancement in Portable Audio Devices PDF Author: Arun Thirugnanasambandam
Publisher:
ISBN:
Category : Digital music players
Languages : en
Pages : 0

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Book Description
Low bitrate audio coding is an enabling technology for a number of applications such as digital radio, Internet streaming and mobile multimedia applications. Using perceptual codecs at low bitrates however has disadvantages. Below 128 kbps, the perceived audio quality deteriorates significantly because of the limited bandwidth and often creates annoying artifacts. Spectral Band Replication (SBR) is a technique that significantly improves the compression efficiency of perceptual audio codecs and the quality of audio, by reconstructing the high frequency components of an audio signal on the decoder side. The missing fundamental is a phenomenon exhibited by a sound when the overtones suggest a fundamental frequency but the sound lacks a component at the fundamental frequency itself. This concept could be used to create a low frequency pitch perception in small speakers, which do not actually have the capabilities to reproduce such low frequencies. This thesis is an attempt to combine these two techniques (SBR and missing fundamental) to improve the quality of audio in portable audio devices.

Journal of the Audio Engineering Society

Journal of the Audio Engineering Society PDF Author: Audio Engineering Society
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 816

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Book Description


Digital Speech Transmission

Digital Speech Transmission PDF Author: Peter Vary
Publisher: John Wiley & Sons
ISBN: 0470031751
Category : Science
Languages : en
Pages : 644

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Book Description
The enormous advances in digital signal processing (DSP) technology have contributed to the wide dissemination and success of speech communication devices – be it GSM and UMTS mobile telephones, digital hearing aids, or human-machine interfaces. Digital speech transmission techniques play an important role in these applications, all the more because high quality speech transmission remains essential in all current and next generation communication networks. Enhancement, coding and error concealment techniques improve the transmitted speech signal at all stages of the transmission chain, from the acoustic front-end to the sound reproduction at the receiver. Advanced speech processing algorithms help to mitigate a number of physical and technological limitations such as background noise, bandwidth restrictions, shortage of radio frequencies, and transmission errors. Digital Speech Transmission provides a single-source, comprehensive guide to the fundamental issues, algorithms, standards, and trends in speech signal processing and speech communication technology. The authors give a solid, accessible overview of fundamentals of speech signal processing speech coding, including new speech coders for GSM and UMTS error concealment by soft decoding artificial bandwidth extension of speech signals single and multi-channel noise reduction acoustic echo cancellation This text is an invaluable resource for engineers, researchers, academics, and graduate students in the areas of communications, electrical engineering, and information technology.

An Application of Spectral Translation and Spectral Envelope Extrapolation for High-frequency Bandwidth Extension of Generic Audio Signals

An Application of Spectral Translation and Spectral Envelope Extrapolation for High-frequency Bandwidth Extension of Generic Audio Signals PDF Author: Alexai Kontsevoi
Publisher:
ISBN:
Category :
Languages : en
Pages : 50

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Book Description
The scope of this work is to introduce a conceptually simple yet effective algorithm for blind high-frequency bandwidth extension of audio signals, a means of improving perceptual quality for sound which has been previously low-pass filtered or downsampled (typically due to storage considerations). The algorithm combines an application of the modulation theorem for discrete Fourier transform to regenerate the missing high-frequency end of the signal spectrum with a linear-regression-driven approach to shape the spectral envelope for the regenerated band. The results are graphically and acoustically compared to those obtained with existing audio restoration software for a variety of input signals. The source code and Windows binaries of the resulting algorithm implementation are also included.

Digital Speech Transmission and Enhancement

Digital Speech Transmission and Enhancement PDF Author: Peter Vary
Publisher: John Wiley & Sons
ISBN: 1119060982
Category : Technology & Engineering
Languages : en
Pages : 596

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Book Description
DIGITAL SPEECH TRANSMISSION AND ENHANCEMENT Enables readers to understand the latest developments in speech enhancement/transmission due to advances in computational power and device miniaturization The Second Edition of Digital Speech Transmission and Enhancement has been updated throughout to provide all the necessary details on the latest advances in the theory and practice in speech signal processing and its applications, including many new research results, standards, algorithms, and developments which have recently appeared and are on their way into state-of-the-art applications. Besides mobile communications, which constituted the main application domain of the first edition, speech enhancement for hearing instruments and man-machine interfaces has gained significantly more prominence in the past decade, and as such receives greater focus in this updated and expanded second edition. Readers can expect to find information and novel methods on: Low-latency spectral analysis-synthesis, single-channel and dual-channel algorithms for noise reduction and dereverberation Multi-microphone processing methods, which are now widely used in applications such as mobile phones, hearing aids, and man-computer interfaces Algorithms for near-end listening enhancement, which provide a significantly increased speech intelligibility for users at the noisy receiving side of their mobile phone Fundamentals of speech signal processing, estimation and machine learning, speech coding, error concealment by soft decoding, and artificial bandwidth extension of speech signals Digital Speech Transmission and Enhancement is a single-source, comprehensive guide to the fundamental issues, algorithms, standards, and trends in speech signal processing and speech communication technology, and as such is an invaluable resource for engineers, researchers, academics, and graduate students in the areas of communications, electrical engineering, and information technology.

Digital Systems and Applications

Digital Systems and Applications PDF Author: Vojin G. Oklobdzija
Publisher: CRC Press
ISBN: 0849386209
Category : Computers
Languages : en
Pages : 992

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Book Description
New design architectures in computer systems have surpassed industry expectations. Limits, which were once thought of as fundamental, have now been broken. Digital Systems and Applications details these innovations in systems design as well as cutting-edge applications that are emerging to take advantage of the fields increasingly sophisticated capabilities. This book features new chapters on parallelizing iterative heuristics, stream and wireless processors, and lightweight embedded systems. This fundamental text— Provides a clear focus on computer systems, architecture, and applications Takes a top-level view of system organization before moving on to architectural and organizational concepts such as superscalar and vector processor, VLIW architecture, as well as new trends in multithreading and multiprocessing. includes an entire section dedicated to embedded systems and their applications Discusses topics such as digital signal processing applications, circuit implementation aspects, parallel I/O algorithms, and operating systems Concludes with a look at new and future directions in computing Features articles that describe diverse aspects of computer usage and potentials for use Details implementation and performance-enhancing techniques such as branch prediction, register renaming, and virtual memory Includes a section on new directions in computing and their penetration into many new fields and aspects of our daily lives

Low-power Audio Input Enhancement for Portable Devices

Low-power Audio Input Enhancement for Portable Devices PDF Author: Heejong Yoo
Publisher:
ISBN:
Category : Analog electronic systems
Languages : en
Pages :

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Book Description
With the development of VLSI and wireless communication technology, portable devices such as personal digital assistants (PDAs), pocket PCs, and mobile phones have gained a lot of popularity. Many such devices incorporate a speech recognition engine, enabling users to interact with the devices using voice-driven commands and text-to-speech synthesis. The power consumption of DSP microprocessors has been consistently decreasing by half about every 18 months, following Gene's law. The capacity of signal processing, however, is still significantly constrained by the limited power budget of these portable devices. In addition, analog-to-digital (A/D) converters can also limit the signal processing of portable devices. Many systems require very high-resolution and high-performance A/D converters, which often consume a large fraction of the limited power budget of portable devices. The proposed research develops a low-power audio signal enhancement system that combines programmable analog signal processing and traditional digital signal processing. By utilizing analog signal processing based on floating-gate transistor technology, the power consumption of the overall system as well as the complexity of the A/D converters can be reduced significantly. The system can be used as a front end of portable devices in which enhancement of audio signal quality plays a critical role in automatic speech recognition systems on portable devices. The proposed system performs background audio noise suppression in a continuous-time domain using analog computing elements and acoustic echo cancellation in a discrete-time domain using an FPGA.

Audio Bandwidth Extension

Audio Bandwidth Extension PDF Author: Erik Larsen
Publisher: John Wiley & Sons
ISBN: 0470858656
Category : Technology & Engineering
Languages : en
Pages : 312

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Book Description
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.

The Computer Engineering Handbook

The Computer Engineering Handbook PDF Author: Vojin G. Oklobdzija
Publisher: CRC Press
ISBN: 1439833168
Category : Computers
Languages : en
Pages : 1648

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Book Description
After nearly six years as the field's leading reference, the second edition of this award-winning handbook reemerges with completely updated content and a brand new format. The Computer Engineering Handbook, Second Edition is now offered as a set of two carefully focused books that together encompass all aspects of the field. In addition to complete updates throughout the book to reflect the latest issues in low-power design, embedded processors, and new standards, this edition includes a new section on computer memory and storage as well as several new chapters on such topics as semiconductor memory circuits, stream and wireless processors, and nonvolatile memory technologies and applications.

The Proceedings of the AES ... International Conference

The Proceedings of the AES ... International Conference PDF Author:
Publisher:
ISBN:
Category : Sound
Languages : en
Pages : 192

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Book Description