Audio on your computer -- Overview

by Ursula Hoffmann

Requirements:
a fast hard disk with lots of free space, a good sound card on your own computer, headphones or speakers, and perhaps a microphone.
Note that audio is not enabled in the ITC classrooms so your targeted audience will have to listen at home. If you do need sound in one of these classrooms, provide it the old-fashioned way, with a battery powered player to play your tape or CD--there are no wall outlets--or with al notebook plus speakers.

Software:
Any Windows version includes Recorder (for creating small sound clips); XP also includes Windows MovieMaker.
You may need to add some viewers, browser plug-ins, at no cost, such as RealOne and QuickTime. See below.
And you may need some software for editing, converting, compression. Try the free CoolEdit demo.

Creating a small sound clip – WAVE format (not compressed, big file size, slow download) -- examples:

  1. Using a microphone plugged into sound card line in, you can record directly: open Recorder, click Record, speak, then click Stop and save as *.wav.
  2. OR, using a tape recorder, you can record voice and/or music.
  3. Then plug a cable into tape recorder line out (this is usually the plug used for the headphones) and plug the other end into the sound card line in.
  4. Open your audio application and select the recording source, here, tape.
  5. Click Record while playing your tape. Then click Stop and save as *.wav.
  6. Open your Wave editor, edit your file, save.
  7. OR you can copy material from a CD -- with steps 4 to 6.
  8. OR you can use a keyboard or other electronic instrument to produce music in MIDI format.
  9. OR you can download a freeware sound file from the Web.

Viewers and Browser Plug-ins: <>These are software packages that let you hear sound on your desktop or from within your browser. 
The most common ones (bolded) -- with suffix(es) indicating file format(s):
File format(s)
(import/export)
File type Windows 
Media Player
RealOne
Player
Quick
Time
asf Active Stream Format y y
aiff AIFF audio -- QuickTime file y y
au AU audio file y y y
avi video file -- QuickTime y y
gif animated GIF file
y y
mid, midi MIDI audio file y
y
mpeg MPEG video file y y y
mpeg2 MPEG2 video (on most DVD discs)


mp3 MP3 audio y y y
pdf Adobe Acrobat -- "sheet music"

y
png Portable Network Graphics image file
y y
ra, rm, rm? RealAudio or RealMedia file
y
swf Macromedia Shockwave Flash file
y
wav WAVE audio file y y y
wma Windows Media Audio file y y
wmv Windows Media Video file y

Each plug-in works with different file formats. Having all three suffices for basic use. Make sure you associate them according to your preference.
Most of them can be upgraded, and for a fee to a better version for more professional use.
But do keep in mind that your targeted audience needs a plug-in to see the file format you are using.

Check your Netscape Help, About Plug-ins, to see what plug-ins are already installed on your computer, and download or purchase and install any others you may need.


Digital audio file formats

WAV --
MS Windows and NT operating systems -- for recording and playback of recorded sound. Easy to create with Recorder but playable only on a PC. Also, the file is not compressed, therefore it is typically larger and takes longer to download. Use it for short sound clips only.

AU --
standard for Unix computers. Most Web browsers include the capability to play “AU” files directly. so it makes the format a good choice for Internet work that will be received by a larger Net audience. This type of file, like the Microsoft WAV format, can be larger than other types of audio files, so it is best used for short sound clips for effective download times. When using AU files on a Web page, you will need to use an outside program (such as the shareware package CoolEdit or the commercially available program Sound Forge) to load the WAV you have recorded and convert it to AU format.

Real Audio (RA) --
Real Audio and Real Video are free downloadable “plug-ins”. You can obtain a free encoder to convert files from WAV to Real Audio format. Real Audio and Real Video files use compression schemes to make a file small for Internet use – some loss of quality is apparent, but you can control what type of compression you wish to use for the file, depending on the target audience and recorded contents.

MP3 (MPEG Audio) --
MPEG audio is a standard for high-quality audio and video files that has gained widespread use. Many companies offer free players capable of playing or creating MPEG files. This compressed format offers the advantage of high quality with a smaller file size. CD-quality MP3 sound files can still be large, however, for use on a Web page that may be downloaded through a typical dial-up modem connection.
The end users will have to have an audio player on their computers capable of handling the format.


Links/Sources on the web:
Duke CIT Resource Guides  audio workstation  --

Audio guide for web developers:  http://www.walthowe.com/pubweb/audio.html
Comprehensive list of audio file formats: http://www.sonicspot.com/guide/fileformatlist.html
About digital audio files:  http://www.arboretum.com/support/manuals/manual_hvst/Files/hppc_digital_audio.html
Windows Media Player multimedia file formats:  http://support.microsoft.com/default.aspx?scid=kb;EN-US;316992 


last revised March. 2005 --