Artists in Virtual Spaces

John Sappington -

Students will learn the basics of digital audio production and presentation with a focus toward presentation via the network based technologies.

Reading List:

The theory of digital sound


Resources List:
Technical Resources

Adobe Technical Guide to Digital Audio

Sound Forge Manual - Download

Peak Manual - Download

Acid Xpress - Download

Apple Music and Audio

Pure Mac

The Recording Website

Pro Tools
Welcome To Digidesign
Digidesign mag
Digidesign Training & Education
Digidesign Training Reference Guides
Links We Like — Inside & Outside Resources

Digital Audio Theory and Reality
Digital Audio
Welcome to BIAS!

Application Notes:

About Shockwave Audio

Shockwave Audio is a technology that makes sounds smaller and plays them faster from disk or over the Internet.

Shockwave Audio can compress the size of sounds by a ratio of up to 176:1 and is streamable, which means Director doesn't have to load the entire sound into RAM before it begins playing. Director starts to play the beginning of the sound while the rest of the sound is still streaming from its source, whether coming from disk or over the Internet. When used properly, the Shockwave Audio compression and streaming features provide fast playback of high-quality audio, even for users with relatively slow modem connections to the Internet.

Compression quality in Shockwave Audio

Although Shockwave Audio uses advanced compression technology that alters original sounds as little as possible, the more a sound is compressed the more it is changed.

Set the amount of compression by choosing a bit rate setting in any of the Shockwave Audio Xtras. The bit rate is not related to sampling rates you may have used in other audio programs. Try compressing the same sound at several different bit rates to see how the sound changes.

Choose the bit rate appropriate for the intended delivery system (modem, ISDN, CD-ROM, hard disk, and so on), the type of movie, and the nature of the sound itself. Voice-over sound quality, for example, may not need to be as high as that of music. Test the sound on several systems to find the right balance between quality and performance.

The more compressed a sound is, the faster it streams. If you choose to use a high quality and low degree of compression, a slow delivery system may not be able to send the data fast enough, resulting in gaps during playback. Most developers choose 16 Kbps for the best results over the Internet.

The following table suggests some general guidelines for setting the bit rate for different delivery systems. It also provides a rough estimate of perceived quality for different rates of compression. Note that real transmission times may be slower than the times shown in this table, depending on network traffic and server load. Delivery
Bit rate

64 to 128 Kbps
Equal to source material

32 to 56 Kbps
FM stereo to CD

28.8 modem
16 Kbps
FM monaural or good-quality AM

14.4 modem
8 Kbps

Note: Any sound compressed at less than 48 Kbps is converted to monaural.

µ-Law 2:1
Useful for exchanging audio with applications on platforms (such as many UNIX workstations) where µ-Law is a standard audio format. µ-Law is used for digital telephony in North America and Japan. (The first letter of the codec name is a Greek letter pronounced Mu.)

16-bit Big Endian and 16-bit Little Endian
Useful when audio must be stored using Big Endian or Little Endian (byte order) encoding, such as when preparing microprocessor-specific audio. These codecs are useful for hardware and software engineers but are generally not useful for video editing.

24-bit Integer and 32-bit Integer
Useful when the audio data must be stored using 24-bit or 32-bit Integer encoding, such as when preparing microprocessor-specific audio. These codecs are useful for hardware and software engineers but are generally not useful for video editing.

IMA 4:1
Useful for cross-platform audio for multimedia. IMA 4:1 was developed by the IMA using ADPCM.

32-bit Floating Point and 64-bit Floating Point
Useful when audio must be stored using 32-bit or 64-bit floating point encoding, such as when preparing microprocessor-specific audio. These codecs are useful for hardware and software engineers but are generally not useful for video editing.

ALaw 2:1
Similar to µ-Law, but used primarily for digital telephony in Europe.

MetaSound/MetaVoice Codecs (Mac OS only)
A wide series of codecs developed by Voxware. These codecs discard parts of the audio signal that are imperceptible to the human ear so the compression provides high music quality with high compression. The codecs cover a wide range of bit rates from AC06 V2.0 at 6,000 bps to the ACS96 V2.0 at 96,000 bps i order to accommodate varying bandwidths.

Qualcomm PureVoice
Intended for speech; works best at 8 kHz. Based on the Code Division Multiple Access (CDMA) technology standard for cellular telephony.

QDesign Music Codec
Useful when compressing high-quality music for Internet distribution. It is capable of delivering CD-quality (16-bit, 44.1 kHz) audio over a 28.8 Kbps line.

MACE 3:1 and MACE 6:1
Useful as a general-purpose audio codec. The Macintosh Audio Compression and Expansion codec (MACE) has been built into the Mac OS Sound Manager for many years. MACE 3:1's lower compression ratio provides higher quality than MACE 6:1. Because it is provided with QuickTime 3.0 and later, it is also accessible in Windows when QuickTime is installed.

MPEG Layer-3 Codec
Also known as MP3. This is the third coding scheme for MPEG audio compression. MPEG Layer-3 uses perceptual audio coding and psychoacoustic compression to remove parts of the audio signal that are imperceptible to the human ear. The result is a compression ratio up to 12:1 without loss of audio quality. MP3 is a common format for distributing music files over the Internet.
A net-based codec using frame-concatenation and interlacing for improved music quality. allows a dual-rate bit-rate of 8.5/6.5 kbps or a fixed-rate bit-rate of 5.0 kbps.

More fully known as Microsoft® Windows Media™ audio compression. This is the standard codec for Microsoft Active Streaming Format which combines fast encoding with high music quality and is optimized for Pentium II (MMX) and Pentium III (SSE/SIMD) processors. WM-AUDIO has a wide bit-rate range from 5 kbps to 128 kbps and offers high quality sound over the Internet even over 28.8 modems. WM-AUDIO is considered a future replacement for MP3.

Indeo® Audio Software
Useful for music and speech distributed over the Internet. Its maximum compression ratio is 8:1. This codec is designed to work together with the Indeo Video codec.

Microsoft G.723.1
A codec intended for use in video conferencing. It offers acceptable voice quality, but is a poor choice for music or sound effects. The audio quality is lower than other codecs that use the same data rate.

L&H Codecs
Speech and music compression algorithm developed by Lernout & Hauspie™.

Useful for speech over the Internet at low data rates.

Microsoft GSM 6.10
Useful for speech, used in Europe for telephony.

Microsoft CCITT G.711
This codec uses µ-Law encoding and is commonly used for digital telephony in North America and Japan.

A Microsoft implementation of Adaptive Differential Pulse Code Modulation (ADPCM), a common digital audio format capable of storing CD-quality audio.

Microsoft IMA ADPCM
An implementation of ADPCM, useful for cross-platform audio for multimedia, developed by the Interactive Multimedia Association (IMA).

3D sound

Soud Synthesis info

Sound Forge 4.5

List of Real Time Softare Synthesizers for PC

Sound synthesis - general

Sound synthesis by physical modeling - IRCAM

Physical Modeling (IRCAM)

Sound synthesis by physical modeling - Italy

Fourier Synthesis:

Chaotic/Fractal synthesis

Chaotic sound synthesis

Genetic Algorithms


online voice/speech synthesis
A research version of Next-Generation Text-To-Speech (TTS) from AT&T Labs

Fourier synthesis (additive synthesis)


CSound for MAC


Paul Lansky


Week 1
– Introductions


# 1 - Submit a Microsoft word file containing a paragraph which briefly describes your audio project. Describe original audio sources, intended output format and/or use. What programs will be required to complete this project? What other media will be used in conjunction with the audio. (web pages, graphics, video, animation, etc.). This file should be named as follows: firstinital, lastname.1.(wav or aiff) – jsappington.1.doc

# 2 – Copy to my drop box a first draft of your audio file(s)as 16 bit, 44.1k .wav or .aiff file(s). This file should be named as follows: firstinital, lastname.2.(wav or aiff) – jsappington.2.wav

#3 – Copy to my drop box your final draft of the audio recording in a 16 bit, 44.1k wav or aiff file. This file should be named as follows: firstinital, lastname.3.(wav or aiff) – jsappington.3.wav

#4 – Final – copy to my drop box the final presentation of your project. Minimum size is 1 minute in length and must contain a combination of 3 sources (Sources may include: cd audio, mp3s, collected wav or aiff files, field recordings ( personal recordings made from real to life sources). Presentation may take any of the forms described in your original proposal ( Flash, embedded in HTML or as a 16 bit stereo/ wav. or aiff) If you are sumbitting a wav or aiff file please include playlist information within the file and complete the authorship summary. This file/folder should be named as follows: firstinital, lastname.4 ( if individual files must include (.wav or .aiff) .

Week 2 
– Peak/Sound Forge basic capture and track extract.
Week 3
– file types / exporting to various delivery applications ( html, streaming, interactive) - recording basics
Week 4

- Digital Signal Processing / Effects

- Begin class project outline -

Week 5

– Mixing Digital Signal Processing / Effects / Preparing Sound for distribution.

Distributing audio via the Web (basics)

Assignment: bring in source audio / recordings/music & individual project descriptions

Week 6
Submit First Draft - #2
Week 7            (10/1)

MIDI and the Web


Week 8
 - Submit Final Draft - #3
Week 9            (10/15)

– Final Presentations & Critique - #4