The earphone is a symbol of the human body's portable audio. Mobile phone headsets are divided into two standards: the OMTP standard is often called the national standard, and the CTIA is called the international standard. Headphones are classified according to their switching modes, mainly including moving coil mode, moving iron mode, electrostatic type and other magnetic type. Classification from the structural functional mode can be divided into semi-open and closed; from the wearing form, there are earplugs, ear-hooks, in-ears and head-mounted; from the number of wearers, there are single earphones and Multi-person headphones; from the sound source, can be divided into active headphones and passive headphones; active headphones are often referred to as card headphones.
The price range of earphones ranges from a few yuan - hundreds of thousands of yuan, the average price is generally around 20 yuan, and the slightly better price is around 400 yuan. If it is a head-mounted type, the price is usually higher. Top-quality headphones, such as limited-edition headphones produced by some top brands, can cost hundreds of thousands of yuan or more.
R stands for the right channel and L stands for the left channel.