Audio Digitization: How It Works Part 2
In order for the computer to understand these numbers, let’s translate these numbers into the binary number system. For simplicity, we assume that a number occupies exactly 1 byte of memory, but in reality, the more bytes allocated to the number, the more accurate the measurement and sound quality will be. After translation, we get:
00000101
00000111
00001010
…
11101011
Computers can already understand and reproduce this sequence as sound.
how to play sound now
• Use speakers or headphones—anything that “pushes air” (ie, produces sound waves). There will be air vibrations in the speakers.
• Apply some power to the speaker. Depending on the strength of the current, the speaker’s voice coil moves in different ways.
• To get this variable current, a special chip called a DAC, a digital-to-analog converter, is required. It takes a number as input and produces a stream as output. All smartphones and computers have these DACs.
All:
1. The processor sends the sound file numbers to the DAC.
2. The DAC receives numbers and outputs different streams based on those numbers.
3. The current is sent to the speaker.
4. The speaker starts to move the speaker cone due to electricity.
5. The cone begins to push the air in front of it, creating sound waves.
6. Sound waves reach our ears and we perceive them as sound.
Whats Next
There is a problem with this approach: the file is too large to be convenient to use. Picture this: 44,000 numbers in one second!
To reduce file size, they propose two solutions: lossy compression and lossless compression. The next article will discuss lossy and lossless compression separately, although they have a lot in common.
