Audio Bit Depth
Audio bit depth is the actual information in the audio file for each sample. The audio bit depth has different amounts of information, this is why you have audio bit depth of 8, 16, 24, 32, 48 and 64-bit. These respond to the quality of the sample. So the bigger the audio bit depth the higher quality the information is.
The "Bit" in Audio Bit Depth
A "bit" is an abbreviation for a single binary digit. Binary is a set of numbers that are either 1 or 0. More than one digit makes it a binary word. Audio Bit Depth of 16-bit could be 0101100101010101, 8-bit could be any combination of binary to make a word of 8 numbers.
What Does Audio Bit Depth Information Mean?
The audio bit depth information is the detail to the range of amplitude steps and this is the only information explicitly expressed in the information. Audio bit depth also plays a main part in signal to noise ratio. But sticking with amplitude first each level of the signal will be broken into steps in the file. Again the higher the audio bit depth the more detail. This only applies to digital PCM files (more on that later)
16 Bit = 65,536 Steps
24 Bit = 16,777,216 Steps
Signal to noise ratio comes into play because obviously the more steps you have then the closer or further amplitudes are lumped together. OK it's not so dramatic but for instance 16-bit achieves signal to noise ratio theoretical maximum of 96.33 dB where as 144.49 dB for 24-bit. 32-bit goes even hirer to 192.66 dB and so on.
Noise such as Dither, which comes from rounding errors and positions can be avoided from 24-bit audio bit depth files because the digital converter itself is louder than any dither that can be applied.
Dynamic range is also a part because the more steps and integers you have the higher the dynamic range. Again the audio bit depth of 16 has around 96 dB of range and 24-bit is 144 dB. There are again limits in the electronics themselves so this is limited even more but varies per device.
Coming back to different types of files such as PCM and why it counts, which is a type of audio format such as WAV whereas MP3 isn't. Have a look at the full explanation: PCM. take into account bit depth information.
Please leave any free comments below about what you have read and if I can make it easier to understand.