BBC Science Focus Magazine expert explainsIn fact, paying attention to the designations L or R on headphones is very important. This helps to improve the sound perception process. Read more about this in the article.Discuss
The brain can detect this difference in just 10 microseconds. Therefore, we can immediately understand that someone is speaking to our left, because it takes a little longer for the sound to reach the right ear.
Knowing this feature, headphone manufacturers mark which earpiece is for the left ear and which is for the right. This allows you to create the illusion that the music comes from everywhere. That is, as if it sounds at the same time near the right and near the left ear. True, this applies to stereo sound, not mono.
Source: BBC Science Focus Magazine