Computing Reviews
Today's Issue Hot Topics Search Browse Recommended My Account Log In
Review Help
Search
Audio bandwidth extension : Application of Psychoacoustics, Signal Processing and Loudspeaker Design
Larsen E., Aarts R., John Wiley & Sons, 2004. Type: Book (9780470858646)
Date Reviewed: May 12 2005

This unique book is intended for sound and digital audio engineers. It explains, in detail, the principle of perceptual enhancement of reproduced sound, from an apparatus limited in resources (such as a loudspeaker), or from audio material limited in frequency (such as compressed audio). This enhancement is based on the capabilities of human hearing, namely, that we infer, or in a way “reconstruct,” missing components from judiciously formed clues. In the low-frequency arena, this is accomplished mostly with nonlinearities, which produce frequency components that help the ear to infer the missing bass, not unlike some clever old designs for tube amplifier/output transformer assemblies. For high frequencies, the main principle is based on extrapolating from the available spectral shape.

The book contains eight chapters and one appendix. It begins with a brief introduction to the subject of bandwidth extension, mainly explaining what the meaning of bandwidth extension is in the audio framework. Chapter 1 provides concise and up-to-date information about signal processing, auditory perception, and loudspeaker particularities relevant to the design and implementation of bandwidth extension methods. The next few chapters delve into the core subject. Chapter 2 is concerned with psychoacoustic bandwidth extension for low-frequency signals, including a discussion of virtual bass and ultra bass experiments. The next chapter is concerned with physical bass enhancement, namely, when the loudspeaker can reproduce low-frequency contents. Also discussed is the combination of physical and psychoacoustical low-frequency enhancement. Chapter 4 presents design issues in loudspeakers for low-frequency bandwidth extension. The theme of chapter 5 is high frequency bandwidth! extension. Included is a discussion of nonlinear/filtering methods, similar to the ones used in some software synthesizers, as well as spectral band replication, the method adopted for the new generation of MP3 coding, and also as a tool in MPEG-4 audio. A slight criticism is that more pages should have been devoted to spectral band replication (SBR).

Chapter 6 details bandwidth extension methods for speech, particularly for coded speech. Chapter 7 is an interesting short chapter on combating noise with the help of bandwidth extension methods. Chapter 8 presents a quite detailed list of patents related to audio bandwidth extension. The appendix presents a mathematical framework for attempting to quantify the outcomes of qualitative experiments. In conclusion, this book is well written, and full of information on bandwidth extension for audio signals that is difficult to find in other sources; it is recommended to anyone involved in audio or digital audio design.

Reviewer:  Vladimir Botchev Review #: CR131265 (0604-0364)
Bookmark and Share
 
Sound And Music Computing (H.5.5 )
 
 
Audio Input/ Output (H.5.1 ... )
 
 
Signal Processing (I.5.4 ... )
 
 
Communications Applications (H.4.3 )
 
 
Input/ Output Devices (B.4.2 )
 
Would you recommend this review?
yes
no
Other reviews under "Sound And Music Computing": Date
Music, cognition, and computerized sound
Cook P., MIT Press, Cambridge, MA, 1999. Type: Book (9780262032568)
Jul 1 1999
Linux music & sound
Phillips D., No Starch Press, San Francisco, CA, 2000.  399, Type: Book (9781886411340)
Aug 1 2001
Machine musicianship
Rowe R., MIT Press, Cambridge, MA, 2001.  399, Type: Book (9780262182065)
Aug 1 2001
more...

E-Mail This Printer-Friendly
Send Your Comments
Contact Us
Reproduction in whole or in part without permission is prohibited.   Copyright 1999-2024 ThinkLoud®
Terms of Use
| Privacy Policy