Syllabus --------------------- Calendar/Schedule --------------------- Lecture Notes --------------------- Projects --------------------- Resources --------------------- Student Work				Art 344B Lecture Notes Digital Audio for Multimedia Projects Digital audio can be incorporated into web pages through Flash, Javascript and HTML to create looping background sounds, audio prompts associated with interactive buttons and other time-based sound effects. Obtain digital samples from royalty-free sound effects CD collections (sometimes found in your local library), by purchasing individual samples on the web (see Resources), or by recording them yourself. Free sounds are also available at numerous websites (see Resources). All audio samples used in class projects sound be from royalty-free sources or recorded yourself. There are many digital sound formats avaialble. We will use AIFF (Mac format), WAV (PC format) and MP3 in our projects. Other formats available are AU, MIDI, REAL AUDIO, etc. Using iTunes to digitize CD sound tracks: Use iTunes to preview the tracks on the CD you with to sample. For short event sounds we will use the AIFF (Mac format) or WAV (PC format). For longer tracks use MP3. Change your iTunes preferences for Importing to AIFF Encoder (use WAV on PCs) or MP3. Set import settings to 'mono' 16-bit. Uncheck all tracks except the ones you wish to import (hold down control key for menu). From iTunes Advanced menu select "Convert to Selection to AIFF, Wav or MP3." Select & drag the track to the desktop to edit in Audacity. Using Audacity to edit digitized sound tracks: Create a new doc in Audacity. Import audio through Project menu> Import Audio. Edit the sound by selecting and deleting parts or it, copy & pasting pieces to new files, etc. It is a good idea to delete dead space at the beginning and end of the waveform. Effects such as Fade Out or Echo can also be applied to the waveform from the Effects menu. The last step will be to downsample your file by changing Project Rate (in lower lefthand corner) to 22.050 kHz or 11.025. Save the editing track through File> Export as AiFF, WAV or MP3. If you would like to mix multiple tracks together try using Adobe's Soundtrack. Audio sample rates & file sizes: Because audio files contain a lot of data you will need to convert them to a lower sample rate. CD quality audio is 16-bit, 44 kHz. For Web and multimedia distribution, convert CD tracks to mono, 16-bit, 22.050 or 11.025 kHz. Stereo sounds take up twice as much space as mono. Experiment with sampling at lower rates such as 8-bit, testing the sample to see that it is not too distorted. Keep in mind that audio samples with "highs" such as birds singing do not play well at 8-bit as the "highs" become clipped and sound muffled. We are much more sensitive to poor sound quality than poor image quality so it is best to retain sound quality over file size. Note: If you plan to use an entire MP3 soundtrack in Flash you will need to override the MP3 compression settings to optimize the file for your Flash movie. After importing your MP3, locate & select the file within your movie's Library and using the pull-down in the upper right select Properties. Uncheck "use imported MP3 quality" box and set the new compression settings. The bottom of the window lists the new compression size for the MP3. Recording your own sounds through a microphone: You will need to purchase a 3rd party USB microphone such as McNally USB version or use a laptop's built-in microphone. It is a good idea to place the microphone as far as possible from your hard drive to avoid recording the humming sound it makes. Placing the microphone within a box with some type of soundproofing material helps to keep your recording as "clean" as possible. To record, make sure the sound panel's input source is set to the device's name in system preferences. You can now record through Audacity'srecord/playback controls. After recording click "stop" and you will see the recorded waveform appear. Click here, for notes on adding sound to Flash Movies.

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