How a portable player works
How music is stored
We have been covering various players in various shapes and sizes in this section, but we have not discussed how they work. If you understand the basics of how these players work, you can then make a better decision on what is important in a player's operation.
Step 1: Music starts as analog
Most of the music you listen to began as analog (wavelike) sound. Sources include the human voice, a vibrating string on a guitar, or the pounding of a drum. When you hear music live, the waves vibrate your eardrum and your brain picks up that signal as sound.
Step 2: Save those waves
Because you can't always be near the live music source, you must save those waves for later playback. Phonographs did just that, by making a representation of the sound waves into vinyl. This wave was picked up by a stylus and transmitted to speakers that mirrored the sounds created by the original source.
Step 3: Binary format transmits sound
If you want to hear a purer form of music without skips or hiss, durability problems, and you also want it to be extremely portable, then you must have digital music. This method converts the sound wave into series of ones and zeros that represents the original sound wave. Because the information is either one or zero, then the signal is much purer, and easier to move. You can now email or transfer a song in digital format as easily as any other file.
Step 4: More samples = better sound
When you have a digital medium trying to emulate a sound wave with curvy attributes, there will be some missing areas. The more points on the wave you can sample, the more detailed the sound will be. This is called the sampling rate, and a typical (and good) rate is 44,100 times per second.
Step 5: CD sound size
If a sound is sampled at 44,100 times per second, and there are 2 bytes per sample (both right and left channel), then there are 1,411,200 bits per second. This means the average three-minute song will take up 32 megabytes of data. This is lot of data storage, but CDs have plenty of storage for 20 of these songs.