ana1notes
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Data can be broken down into two broad categories - Digital data and analog data. You can think of digital data as something that has discrete units - for example, you can have exactly four cats or two trees (you can't have two and a half cats!). Analog data is infinitely variable, for example you can have many kinds of blue or sound of many different pitches.
A digital clock gives the impression that it tells you "exactly" what time it is. However, this is only an "approximation" of the time restricted by the number of digits the clock has. Consider a "better" digital clock (like a stopwatch) which has 2 decimal places for the seconds. This is more "accurate" but still not as exact as a clock with 4 decimal places for the seconds.
Obviously, we could keep adding decimal places to the digital clock but never know exactly what time it is. This is the problem with trying to convert an analog source into digital form. The process of converting an analog source into a digital approximation is called sampling.
1. Into your notebook, write your own notes describing the difference between analog and digital data. Make sure you give an example.
2. The following link contains some analog sound waves which have been sampled and converted into a digital sound file - »./upload/dellepxe.wav. Note, the file format is wav, which stands for wave, in other words sound waves
You can save this file to your computer by right clicking on the link and choosing save target as..
Use the recorder application (if running windows xp) to open the wav file (after you have saved it to your home directory). You will notice it appears to be scrambled. The recorder programm allows you to manipulate the file. This file has been manipulated in some way. Play with the file and try to put it back to the way it started.
Once you have the file in its original form, write down what is says, into your notes. In your notes, also descibe how you changed the file to find the original sound.
On »this page you created and edited a web page about Digital Media. In this mini-project you will add to this page
1. Use the sound recorder to make your own recording (your teacher can help you out with a microphone). Create message using the recorder. Manipulate the message by reversing, speeding up or slowing down the sound. Save the altered file and place it on your web page. Challenge your web site visitors to decode the secret message.
2. The exercise above would have been very difficult to do using analog techniques. Write 300 words about the following topic, using your experiences in this exercise as an example. Save the essay onto your web page.
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