Audio Card

The audio card is used for playing back sounds and music on the computer. It is also used for recording sound and music. Most Macs have audio hardware built into them, but only at a medium level of quality. PCs come with anything from no audio cards up to music production quality cards. In order to test any sounds I was considering for the project I needed to have a standard quality audio card, so that I would have a good idea of what my audience was likely to hear. I feel it does little good developing fabulous sound for a high-end card when all the average listener gets to hear is strange blats and buzzings. These days the standard for the PC is Creative Labs' Sound Blaster or other cards based on it or compatible with it in some way. I am using a Sound Blaster AWE 64. However, I am aware that a top quality card is worth having, since it is becoming popular to produce CD quality music for a CD-ROM that people can play on their music systems separate from the multimedia production. The games Relentless [Ade95], Tone Rebellion [Log97] and The Neverhood [Ten96] are examples of this with sound tracks worthy of any film score.

When developing sound my main concerns are how much disk space the resulting file is going to take up, general playback quality of the sound compared to the original, realism of specific sounds, how many volume levels (the "dynamic range") I may wish to use, and how swiftly deliverable the sound file will be. These all relate to the sample rate, measured in KiloHertz (KHz), and the sound resolution, how many bits are used to create a sample. The higher the sample rate in KHz and the more bits in each sample, the more storage space is required, and the the dynamic range.

The music for Odysseus, She began as 44Khz CD quality samples. Those samples were then compressed using MPEG I layer 3. MPEG stands for Motion Picture Experts Group and refers to software that complies with the standards they have agreed upon. Since this is for motion pictures, it includes sound. The sound part of the software comes in three layers, each of which provides higher compression, but requires more CPU power and loses more sound fidelity. I was in fact torn as to which layer I should use for Odysseus, She given the resulting file sizes. If I were to deliver Odysseus, She on the Net, then I would need as small a file as I could manage, without losing too much sound fidelity. However, for academic publication purposes, I could be restricted to delivery via a CD-ROM, though that would open up possibilities for better sound.

Given my focus is storytelling and not directly on multimedia production, and given I wanted to make my work available to certain people for assistance during the development process, I opted for the format which provided the most compression, but applied it to relatively high quality samples.