What is the process of assigning audio amplitude to a unique digital code word?

A.
linear prediction

B.
encoding

C.
sampling

D.
quantization

Explanation:
Quantization is the process of assigning a value from the voltage range based on the amplitude of each audio sample. Notice that the Voltage values are not evenly spaced. The spaces near the horizontal line are much closer than the ones at the two ends. This helps our ears distinguish common sounds more easily.