Basic acoustics and Signal Processing for musicians and computer scientists

http://www.linuxfocus.org/English/March2003/article271.shtml

From this excellent article:

This article intends to be educational. It hopes to provide the reader with a basic knowledge of sound and sound processing. Of course music is one of our concerns but all in all, it is just some noise among other less pleasant sounds.
First the physical concepts of sound are presented together with the way the human ear interprets them. Next, signals will be looked at, i.e. what sound becomes when it is recorded especially with modern digital devices like samplers or computers.
Last, up to date compressions techniques like mp3 or Ogg vorbis will be presented.
The topics discussed in this paper should be understandable by a large audience. The author tried hard to use “normal terminology” and particularly terminology known to musicians. A few mathematical formulas pop up here and there within images, but do not matter here (phew! what a relief…).

KRISTAL - get started with recording, mixing and mastering digital audio

http://www.kreatives.org/kristal/

KRISTAL Audio Engine is a powerful multi-track recorder, audio sequencer and mixer - ideal for anyone wanting to get started with recording, mixing and mastering digital audio.

It is designed as a modular system. The main application provides a mixing console, while the audio sequencer, live audio input and so on are loaded as separate Plug-Ins.

KRISTAL Audio Engine is free for personal, educational and non-commercial use.

Soundsnap - free sound effects and loops

http://www.soundsnap.com/browse

Soundsnap is the best platform to find and share free sound effects and loops- legally. It is a collection of original sounds made or recorded by its users, and not songs or sound FX found on commercial libraries or sample CD’s.

Podcasting with Audacity: Creating a Podcast With Free Audio Software

http://www.webreference.com/multimedia/editing_podcasts/

A walk through some of the most common podcast editing tasks that you will want to perform with Audacity.

Royalty free music from Kevin MacLeod

http://incompetech.com/m/c/royalty-free/

Lots of free music. You can search or browse for music by genre.

Exploring sound waves

http://illuminations.nctm.org/ActivityDetail.aspx?ID=37

Frequently sound is described using terms such as pitch, tone, frequency, intensity or loudness. To understand the origins of these terms as well as to understand the mathematical models used to represent sound, this applet can help you to explore the dynamics of a sound wave.

Speech Synthesis for Squeak

http://www.oldenbuettel.de/squeak-doku/Speech-TTS/Speaker.html

Documentation on Squeak class that lets you do speech synthesis. If you use

manWithEditor

you get a nifty dialog with lots of controls that let you adjust the voice.

DSpeech - Free Text to Speech Program

http://dimio.altervista.org/eng/

DSpeech is a TTS (Text To Speech) program with functionality of ASR (Automatic Speech Recognition) integrated. It is able to to read aloud the written text and choose the sentences to be pronounced based upon the vocal answers of the user. It is specifically designed to quickly and directly provide the functions and improved practical usefulness that are requested by this kind of program. In the meantime, the invasiveness and resource consumption is minimal.

Audio Visualization from NASA

http://learn.arc.nasa.gov/mathtrax/features.html

MathTrax has the ability to sound out the graph being drawn to take understanding one step higher.

For example, if a graph line crosses the same axis twice the auditory visualization will indicate that activity.

Audio playback provides a way to “see” what we would normally not be able to. This particular feature is of great use to the vision impaired community.