你说对了，多出4倍的采样点就是可以获得更高的截止频率，而一些并不太好的ADC在进行频率上限截止的时候，有可能会出现失真，但以现在的ADC技术，不必担心这个问题。相关的文献是可以谷歌到的
If 44.1kHz Captures More than We can Hear, Why Use Higher Sample Rates?
There are a couple of reasons that higher sampling rates can be advantageous; the first is that while 44.1kHz is the standard for audio CDs, 48kHz is the standard for audio for video. Studios who regularly work in film and television may use 48kHz as their in-house standard. But higher sample rates such as 88.2kHz, 96kHz, 192kHz, and even higher may have a purpose — and maybe not the one that you think it is.
Remember what the Nyquist theorem states: frequencies below half of the sampling rate can be reconstructed. So what happens to frequencies that are more than half of the sampling rate? The theorem states that any frequencies above the Nyquist Limit will not be rendered properly, and this proved to be true; frequencies above the limit can appear as spurious signals in the audible audio spectrum. This is referred to as “aliasing,” and must be prevented by band-limiting (filtering) the analog audio before it’s converted to a digital format. Effectively, this means that analog-to-digital converters (ADCs) have a low-pass filter at the Nyquist Limit that stops those out-of-bandwidth-frequencies from getting to the converters. The implementation of that filter in the ADC is key; if done well, it should be completely transparent; done poorly, the filter will degrade the quality of the audio. By sampling at 88.2kHz, 96kHz, or even 192 kHz, the implementation of the anti-aliasing filter is moved above the audible frequency range (which means that even less than optimal filter design will be inaudible). This was a much bigger issue with early ADCs, where the filters could audibly degrade the signal. With modern technology, it’s much less of an issue regardless of sample rate.