音频系统中44.1KHz的由来

   Perhaps the most popular sample rate used in digital audio, especially for music content, is 44.1 kHz, or 44,100 samples per second. The short answer as to why it is so popular is simple; it was the sample rate chosen for the Compact Disc and, thus, is the sample rate of much audio taken from CDs, and the default sample rate of much audio workstation software. 
   As to why it was chosen as the sample rate for the Compact Disc, the answer is a bit more interesting. In the 1970s, when digital recording was still in its infancy, many different sample rates were used, including 37kHz and 50 kHz in Soundstream’s recordings [6]. In the late 70s, Philips and Sony collaborated on the Compact Disc, and there was much debate between the two companies regarding sample rate. In the end, 44.1 kHz was chosen for a number of reasons. According to the Nyquist theorem, 44.1 kHz allows reproduction of all frequency content below 22.05 kHz. This covers all frequencies heard by a normal person. Though there is still debate about perception of high frequency content, it is generally agreed that few people can hear tones above 20 kHz. This 44.1 kHz also allowed the creators of the CD format to fit at least 80 minutes of music (more than on a vinyl LP record) on a 120 millimeter disc, which was considered a strong selling point. But 44,100 is a rather special number: 44,100 = 2^2 × 3^2 × 5^2 × 7^2, and hence, 44.1kHz is actually an easy number to work with for many calculations.