Signal to noise ratio discrimination for sound quality

When recycling audio, we can use the signal-to-noise ratio of the audio system to distinguish the quality of the audio system, as follows:

Short for signal-to-noise ratio, it refers to the ratio or decibel difference between the various noises added by the audio frequency after passing through the playback device and the original signal level. Sometimes, it is also represented by the absolute noise voltage value output by the playback device, which is called the noise level.

As mentioned earlier, there is a so-called "masking effect" in human auditory perception, which means that one sound can affect another sound. As long as the intensity of one sound is greater than another sound to a certain extent, the human ear feels that only strong sound is present. So, if the ratio of useful signals to noise is large, which is known as a high signal-to-noise ratio, then the human ear cannot hear the noise and only hears the sound of useful signals. Generally speaking, if the useful signal is 10 times greater than the noise, the useful signal can effectively mask the noise. If it is much lower than this value, the human ear will feel the presence of noise. Indeed, the higher the signal-to-noise ratio, the better, but at the same time, the cost of equipment will increase.