User's Guide Computer Sounds Some computers, like the Mac, can play and record sounds digitally. This is very useful because it allows you to add sounds to presentations, add voice annotation to documents, etc. The sound quality that your computer can deliver depends on the sampling rate. Think of this as if the sounds were dots per inch (dpi) on a printed page. The more dots per inch you have, the better the image will look. The same holds true for sound. The higher the sampling rate, the clearer the sound will be (because you actually record more information at higher sampling rates). As you begin recording, the computer takes “samples” of the sound, rather than recording continuously. If you select a higher rate, the computer will take more samples in the same time, therefore recording a more accurate sound. The Mac can record and play different sampling frequencies such as 5 Khz, 7 Khz, 11 Khz, 22 Khz, etc. When you use low frequency rates, the sound quality is similar to any (low quality) AM radio or a normal phone call. You can tell this low quality sounds by its “tin” sound. The 22 KHz sampling rate gives you a very realistic sound, so we recorded all Sound Clips at a 22 KHz sampling frequency. A real life example of how realistic Sound Clips can get is the “Dog Bark - Big”. As we were editing and playing back the sound, a dog outside began to bark back every time we played the sound. You may wonder why anybody would settle for a low sampling rate if 22 KHz gives you a much better sound. The reason is simple, as 22 KHz packs so much information, it takes up much more space when you save those sounds to disk. We had to decide whether to have more sounds OR higher quality. For your convenience, we settled on both; 9 disks at the high quality 22 KHz sampling rate. Sound Formats There are several different sound formats on the Mac. The sound format that you use depends on the program where you want to use Sound Clips. The most common formats are: • Sound Format 1 (or “snd1”) • HyperCard Sound format, Sound Format 2 (or “snd2”) • SoundEdit Format We decided to ship Sound Clips in the most standard format: Sound format 1 or “snd1”. The reason is simple: it is very easy to play these sounds under System 7, just double click on any sound. You can also play all your new Sound Clips (or install them anywhere) directly or with the help of the SoundClipper utility under System 6 or 7.