Bit Depth
位深（bit depth） 决定了每次采样时可以记录的振幅个数，位深 越大，每次采样时可以记录振幅变化越细。
常用的 位深 有 16 位、24 位和 32 位三种。
What is audio bit depth?
The audio bit depth determines the number of possible amplitude values we can record for each audio sample. The higher the bit depth, the more amplitude values per sample are captured to recreate the original audio signal.
The most common audio bit depths are 16-bit, 24-bit, and 32-bit. Each is a binary term, representing a number of possible values. Systems of higher audio bit depths are able to express more possible values.[1]