← Back to context

Comment by KozmoNau7

7 years ago

To put things in perspective, 16-bit PCM audio has a noise floor around -96dBFS, ie. the difference between the loudest possible sound the format can contain and the noise floor is 96dB. That's what the bit depth determines; the level of the noise floor in relation to the loudest reproducible sound. It does not add any more detail, it's not like the resolution of an image file, the added bit depth does not allow for finer-grained details, audio doesn't work like that.

96dB is a lot more than you probably think, it's like the difference between an anechoic chamber (nominally ~0dB) and someone jackhammering concrete right next to you (~90-100dB). Add to this that even a quiet room has a noise floor around 20-30dB, and to even hear the noise floor in CD quality audio, a full-scale peak would hit 130dB!

Try generating a sound at 0dBFS, the attenuate it in steps of 10dB and make note of when you can't really hear it anymore. At -50dB the sound is already extremely low and barely audible, and there would still be 46dB of attenuation available.

In addition to this, noise-shaped dither can push the noise floor towards frequencies where the human ear is less sensitive, giving a perceived noise floor of around -120dBFS. In other words, 24-bit audio for distribution and listening is absolutely pointless and has absolutely no audible difference when compared to 16-bit audio.