Digitized Data

In the example of the digitized images of the soccer ball, the number of pixels and the number of shades of grey determine how accurate the image looked.

In audio, the number of times per second that we measure the wave is like the number of pixels.  And how many numbers we use to measure the wave height is like the number of shades of grey.

Just as with the soccer ball, the more times we measure and the more numbers we can assign, the less sampling error there is.

In our audio wave example, measuring 8000 times per second and only using 16 numbers (4 bits) to measure amplitude, we get a lot of sampling error.  If we measure 32000 times per second and use 256 amplitude levels (8 bits), we get much more accuracy.

People who are hard of hearing may need that much accuracy (or "fidelity") to understand the speech.  But there is a price to pay for accuracy.  Our less accurate digitizing method uses 32000 bits per second.  The more accurate method uses 256000 bits per second.  Most telecom systems cannot send and receive data at that speed, so fidelity suffers.

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