Linux Sound HOWTO: http://www.linuxdoc.org/HOWTO/Sound-HOWTO.html
Linux Audio-Quality-HOWTO: http://audio.netpedia.net/aqht.html
Audio FAQ: http://www.faqs.org/faqs/AudioFAQ/
smix is a mixer application, allowing you to adapt the sensitivity of the input to the signal's strength: http://brahms.fmi.uni-passau.de/~anderss/smix/
The birthplace of the Linux sound system is OSS, the open sound system: http://www.opensound.com/
OSS product information: http://www.4front-tech.com/oss.html
Alan Cox has some useful information on free sound drivers at http://www.uk.linux.org/OSS/.
The Advanced Linux Sound Architecture (ALSA) is compatible with OSS and looks superior when several PCI sound cards are needed: http://www.alsa-project.org/.
“ALSA—Advanced Linux Sound Architecture”, Julia Wunner, iX issue #10, 1999, page 98: http://www.heise.de/ix/artikel/1999/10/098/. This on-line article (in German) is a good overview of the ALSA project.
“Benutzung von Audiodaten unter Linux”, Julia Wunner, iX issue #12, 1998, page 54. This article (in German) is not available on-line, but is still a good overview of Linux sound in general.
“Portable Real-Time Applications”, Juergen Kahrs, Linux Journal #66, October 1999, page 72: www.linuxjournal.com/article/3577. Describes how to generate sound on three platforms (Linux, IRIX, Win32) and uses a chaotic Duffing oscillator to produce noise.
If you are looking for Linux sound applications of any kind, you will find them here: http://www.bright.net/~dlphilp/linuxsound/ and http://www.xdt.com/ar/linux-snd/.
Analysis of Observed Chaotic Data, Henry Abarbanel, Springer, ISBN 0-387-94523-7: http://www.zweb.com/apnonlin/
Nonlinear Time Series Analysis, Kantz & Schreiber, Cambridge University Press, ISBN 0-521-65387-8: http://www.theorie.physik.uni-wuppertal.de/Chaos/schreiber/myrefs/book.html
Dynamics: Numerical Explorations, Nusse & Yorke, Springer Verlag, ISBN 0387982647: http://keck2.umd.edu/dynamics/general_info/book.html
Coping with Chaos: Analysis of Chaotic Data and The Exploitation of Chaotic Systems, Ott, Sauer, Yorke, Wiley-Interscience 0-471-02556-9, 1994: http://www-chaos.umd.edu/misc/copingchaos.html
Analyse chaotischer Systeme, Thorsten Buzug, BI-Wissenschaftsverlag, ISBN 3-411-16681-9
Time Series Prediction—Forecasting the Future and Understanding the Past, Weigend & Gershenfeld (editors), Addison-Wesley, ISBN 0-201-62602-0
Introduction to Signal Processing, Sophocles Orfanidis, Prentice Hall, ISBN 0-13-209172-0: http://www.ece.rutgers.edu/~orfanidi/intro2sp.html. A good introduction to linear signal processing, emphasizing hands-on experience with audio applications.
Optimum Signal Processing, Sophocles Orfanidis, McGraw-Hill, ISBN 0-07-100834-9. This introduction to linear adaptive filtering is a very good blend of theory and application.
The Scientist and Engineer's Guide to Digital Signal Processing, Steven W. Smith, ISBN 0-9660176-3-3, http://www.dspguide.com/. A very readable “low math” introduction with many examples. Downloading individual chapters or the entire book is free.
Linux Multimedia Guide, Jeff Tranter, O'Reilly, ISBN 56592-219-0: http://www.ora.com/catalog/multilinux/. The only book about the OSS API is already a bit dated, but most of the API information should still be valid because of the consensus among Linux developers to stay with it.
SAL—Scientific Applications for Linux: http://SAL.KachinaTech.COM/index.shtml
Vancouver Linux Users Group—Science and Engineering SIG FAQ about GNU Linux in Science and Engineering: http://members.home.net/scieng/
sci.nonlinear, Nonlinear Science FAQ: http://amath.colorado.edu/appm/faculty/jdm/faq.html