Foundations of Web Design

Audio

1. General audio concepts - when you create, edit, or convert audio files, you have two choices that directly affect the quality and size of the audio file
   
   
   • bit depth - 8 bit vs. 16 bit; 16 bit sound files have better quality but larger size than 8 bit ones
   • sampling rate - usually in the range from 8 KHz to 48 KHz; the greater the sampling rate, the better the quality but the larger the file size
     
     
2. Two basic types of audio are downloaded audio and streaming audio
   
   
• Downloaded Audio
  
  
  • Web browsers allow an author to embed audio into a Web page. However, the Web surfer may have to wait out a long download. Read this guide to browser supported audio MIME types. You can use the HTML EMBED tag to have downloaded audio play in a Web page.
  • MP3 - MP3 is a very popular audio format. For example, music swapped with Napster is usually in the MP3 format. It is easy to obtain MP3 players for PC's & Mac's. See mp3.com for examples.
  • WAV - .wav, de facto standard for PC's but works with QuickTime on Macs, see example answer machine messages in the .wav format here
  • AIFF - .aif, de facto standard for Mac's
  • u-law - .au, standard for Unix
    
    
• Streaming Audio
  
  
• RealAudio (part of RealMedia) by Real Networks - the Web surfer doesn't have to wait for the full audio file to download.
  
  Listen to this demo if you have the proper RealPlayer plug-in . You will hear a streaming message from me as the page loads. Hear many other examples at real.com.
  
  
• Windows Media by Microsoft- competing with the popular RealAudio format, Windows Media is popular as well.
  
  
3. MIDI - MIDI is a special format that uses synthesized musical instrument sounds to create music. It's advantage is that it uses little bandwidth since a MIDI file is really just a text file. However, MIDI music doesn't sound too realistic in many cases since it does not include voice tracks. Check out www.mididb.com for many MIDI's.
   
   
4. Activity - Add an audio, mp3, or wav file to your home page by using the EMBED OBJECT HTML tag. Click here to visit a page with embedded audio.
   
   
5. Move your mouse here - You can obtain some sound clips at http://www.webplaces.com/html/sounds.htm and at echovibes.com
   
   
6. Integrated audio formats where sound is combined with animation.
   
   
   • Shockwave - great animation and audio, requires the free Shockwave plug-in. Shockwave content is created with Macromedia Director. See the Music section at shockwave.com for examples.
     
     
   • Flash - requires free plug-in, create Flash content with Macromedia Flash, examples (listen closely for the sounds).
     
     Activity: Open Flash and use the Window/Common Libraries/Sounds menu commands to listen to sounds that come with Flash.
     
     
   • Java- requires Java-enabled browser; there is a high learning curve to learning the Java language itself unless you can find a Java applet that is easy to use for sound