“The file size produced by selecting 44Hz sampling rate and 16kbps bit rate is the same as the file size compressed by selecting 8Hz sampling rate and 16kbps bit rate. The sound quality of the two is also almost the same”

I seriously suspect that there is something wrong with your hearing~~

Author: A Pot of Pear Blossom Reply Date: 2005-6-25 16:35:55

The sampling rate is similar to that of dynamic images The number of frames, for example, the sampling rate of the movie is 24 Hz, the sampling rate of the PAL format is 25 Hz, and the sampling rate of the NTSC format is 30 Hz. When we play back the sampled still images at the same sampling rate, what we see is continuous images. By the same token, when a CD recorded at a 44.1kHz sampling rate is played back at the same rate, you can hear continuous sound. Obviously, the higher the sampling rate, the more coherent the sounds heard and the images seen. Of course, the sampling rate that human hearing and visual organs can distinguish is limited. It is basically higher than the sound sampled at 44.1kHz, and most people can no longer notice the difference.

The number of bits in the sound is equivalent to the number of colors in the picture, indicating the amount of data in each sample. Of course, the larger the amount of data, the more accurate the playback sound will be, so that the sound of the kettle will not be compared to the sound of a train. honking confusion. For the same reason, the picture is clearer and more accurate, so as not to confuse blood with tomato sauce. However, due to the functional limitations of human organs, 16-bit sound and 24-bit images are basically the limits of ordinary humans. Higher digits can only be distinguished by instruments. For example, a phone is a 7-bit sound sampled at 3kHZ, while a CD is a 16-bit sound sampled at 44.1kHZ, so the CD is clearer than the phone.

When you understand the above two concepts, bit rate is easy to understand. Taking a phone as an example, if there are 3,000 samples per second and each sample is 7 bits, then the bit rate of the phone is 21,000. The CD has 44100 samples per second, two channels, and each sample is 16 bits, so the bit rate of the CD is 44100*2*16=1411200, which means that the data volume of the CD per second is about 172KB, and a The capacity of a CD is 74 minutes equal to 4440 seconds, which is 763680KB = 745MB.

Wait a minute, the capacity of a CD should be 640MB, which means that at least one of the two previous data, 44.1kHZ sampling rate and 16-bit precision, is inaccurate.

It doesn’t matter. You can find the information for the specific data. Anyway, the concept is like this.

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