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 or tape recorder or digital
keyboard....
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 a notebook plus speakers.
Software:
Any Windows version includes Recorder (for creating small sound clips);
XP also includes
Windows
MovieMaker for video with sound..
You may need to add some viewers, browser plug-ins, at no cost, such as
RealOne and
QuickTime. See below.
And you may want some software for editing, converting, compression.
Try the free downloadable CoolEdit demo version. (More powerful
software packages are quite expensive.)
Creating a small sound clip:
using Recorder (it records/digitizes but is not an editor)
-- in WAVE format (not compressed, big
file size, slow download) -- steps:
- 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.
- OR, using a tape recorder, you can
record voice and/or music.
- 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.
- Open your audio application and select
the recording source, here, tape.
- Click Record before playing your tape.
Then click Stop and save
as *.wav.
- Open your Wave editor (such as
Audacity, see below), edit your file,
save.
- OR you can copy material from a CD --
with steps 4 and 5.
- OR you can use a keyboard or other
electronic instrument to produce music
in MIDI format.
- OR you can download a freeware sound
file from the Web.
A nice illustrated (a bit dated) tutorial on using Recorder, part of
Windows:
Another option, a free download:
Audacity -- a free simple
audio recorder and editor for Windows, Mac, Linux -- it also links to a
free MP3 encoder, LAME-enc.dll which you may already have if you
installed Winamp.
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):
- Adobe Acrobat Reader -- pdf -- free, for seeing and
printing pages
that retain their original look, such as "sheet music.". Used by online
newspapers. If you own Adobe Acrobat for the creation of pdf files it
gets
automatically plugged into your browser. (Get the academic version to
save
money.)
- Apple QuickTime -- free, for Mac and PC audio and video
--
see below
With the free version of QuickTime, you can play and create many kinds
of files, including video, audio, graphics, and virtual (VR) movies.
The
free version of QuickTime includes QuickTime Player, which you can use
to play media located on your computer's hard disk, a CD, or the
Internet.
With the full-featured version, called QuickTime Pro, you can do such
things as play movies full screen, save files from the Internet, edit
audio
and video, add special effects, create slideshows, and convert and save
video, audio, and images to more than a dozen standard file formats.
You
can purchase a registration key to upgrade to QuickTime Pro at
www.apple.com/quicktime. - Macromedia
Flash Player -- a free download but note that RealPlayer also plays
flash files -- see more in /plug-ins/
- Shockwave by Macromedia
- Shockwave Flash -- swf, spl --
- RealPlayer/RealOne Player by RealNetwork -- see below --
the
basic
version is free but the pro version includes an editor
- Java -- comes with Windows to run Java applets
- Windows Media Player -- see below -- comes with Windows
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. And see
Converting below.
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. And see Convert below.
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.
Converting to different formats --
As with images, leave the original audio file untouched. Convert a
copy, once. Generally, you convert to a compressed format, thus losing
data. Therefore, with multiple conversions of a previously converted
file, you incur ever more loss of quality.
Try the free NCH Switch Sound File Conversion Software -- http://nch.com.au/switch/index.html
-- then perhaps upgrade to Switch Plus (full version).
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 Oct 2005
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