The range of the human ear is 20-20K Hz, 120-130dB is the limit of humans, and hearing will be damaged if it exceeds 130dB
Unit of frequency: Hz (Hertz)
Amplitude range: dB (decibels)
Sample rate: How many snapshots of sound waves are captured per second. 48kHz = 48k samples per second
Nyquist theorem: To perfectly record a sound wave with a maximum frequency of f, you need to have a sample rate of at least 2f
For example, the human ear must have a maximum sampling rate of 20kHz → at least 40kHz→ so the audio standard is 44.1/48kHz
Bit depth: The higher the selection, the higher the sound amplitude controllable range. 24bit can achieve a maximum range of 144dB
Bit depth affects dynamic range and noise floor
The higher the number → the small signal is not lost → cleaner and more detailed
The greater the dynamic range→ the difference between loud and quiet can be recorded more cleanly
Each additional 1 bit increases the dynamic range by approximately 6dB
24bit ≈ 144 dB
Quantization Noise: When a sound is digitized, it is forced to round up the error because it “cannot accurately represent the original volume”.
The higher the bit depth, the smaller the error and the cleaner the sound
The lower the bit depth, the greater the error and the more obvious the noise
Noise Floor: The noise floor is “the noise of the device itself”.
The self-noise of the microphone, the noise of the preamp, the noise of the sound card electronic circuit, and the faint electronic noise of the analog device itself are all noise bottoms. The noise floor itself is determined by the device, not the bit depth.
The bit depth does not change the “size of the noise floor”, but it can determine whether the sound below the noise floor can be recorded.
Higher bit depth → finer volume resolution → better distinguishing small sounds close to the bottom of the noise
