Sampling rate

A digital recording of a sound contains numbers that represent the amplitude of a sound at different points in time. Time is continuous and contains infinitely many points. Thus, the amplitude of a sound cannot be recorded for each point in time. It must therefore be sampled.

The sampling rate, also called "sampling frequency", is the rate at which sound is sampled and is usually represented as the number of samples taken in a certain period of time.

For example, a sample rate of 44,100 Hz means that the sound is sampled 44,100 times in each second and the digital recording of the sound contains one value for the amplitude of each channel for every 1/44,100 portion of the second.

Common sampling rates include 22,050 Hz, 32,000 Hz, 44,100 Hz, 48,000 Hz and 96,000 Hz. The sampling rate in an audio CD is 44,000 Hz (or 44.1 KHz). Higher sampling rates provide better sound quality, but require more space for the digital recording. According to the Nyquist-Shannon-Kotelnikov sampling theorem, the sampling rate can only properly represent sound with frequencies up to half of the sampling rate. Thus, a CD can only properly represent sound up to 22,050 Hz. The CD sampling rate is used as 20-22 KHz is considered the upper limit of the human ear. Contemporary digital recording equipment sometimes uses higher sampling rates. The disadvantage of higher sampling rates is: Higher rates use more space. The benefits are not as clear. It is possible that even though the human ear cannot hear frequencies above 20 KHz, it may be able to perceive distortions that higher frequencies have on audible sound. It is also possible that higher frequencies allow for better signal processing with smaller losses in quality (through equalizers, reverbs, etc.).


Considering that humans perceive up to about 20Khz, when doubled that frequency is (44.1Khz)and that should be enough to compensate for the digital interpretation of a given sound or resolution error as opposed to actual analog and true sound, according to Nyquist Shannon Kotelnikov theorem, where the frequency must be at least doubled when attempting to reproduce the sound digitally....
44.1Khz at 32 bit depth equals to 88.2Khz at 16 bit depth in sound resolution "kbps"

I do not see any reason to use higher frequencies with lower resolution in order to reproduce auditable sound frequencies, approximately ~ 20Hz to 20Khz!

What I am saying is: it is better to have more resolution in a given time period than to administer information at a higher rate but lower resolution to the listener...

This makes some sense. You are saying that you can increase the sampling rate, but if you want to keep your sound data the same size, you will have to lower the sampling resolution. Then, you will get some minimal to none improvement in the frequencies you can hear (because of the sampling rate), but you will sacrifice a lot of dynamic range (because of the sampling resolution).

Of course, you can increase the sampling rate and keep the sampling resolution. This just means that you will be using more data. Then you keep your dynamic range with the same sampling resolution. It is not clear that you need the higher sampling rate, because the human year can't deal with anything over 20-22KHz. But some people argue that, even though you can hear higher frequencies, there are sound qualities (ambiance, whatever) that is actually audible, if those higher frequencies are present.

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