Headphones (translated from English means "headphones") is a device designed to listen to music and other sounds (including speech). Let’s get acquainted with the main types of headphones. They are distinguished by the type of construction, by acoustic design, by the type of signal transmission, by the type of connectors, etc. According to the type of design, headphones are overhead and in-ear. On-ear headphones have the speaker outside the ear. They can be of various sizes and shapes. In-ear headphones (they are often called plugs), in turn, are divided into in-ear (preferably due to silicone sound-proofing nozzles) and earbuds. They are placed directly in the ear canal. Due to their compactness, they are very convenient, however, in terms of sound quality they are often inferior to overhead ones. On-ear headphones differ in acoustic design. They are closed and open. Headphones with closed acoustic design are preferable to use in rooms with a high level of noise or in transport. Open-back headphones are good in quiet rooms or on almost silent vehicles (for example, on a yacht). According to the type of signal transmission, there are wired and wireless headphones. Headphones with a wired signal are the most common. Wireless headphones are connected to the source of information using a wireless channel (radio, Bluetooth). The sound quality in these headphones is worse than in wired ones. According to the type of connectors, there are: Jack (6.3mm), Mini-jack (3.5mm), Micro-jack (2.5mm) and USB (used in new generation headphones). Headphones can also differ in technical characteristics: frequency range, sensitivity, resistance, maximum power and distortion level as a percentage. The most famous headphone manufacturers: Apple, Panasonic, Philips, Sony and others. Remember that prolonged use of headphones is fraught with partial hearing loss and may even lead to deafness, so be careful! The safest are large headphones, they concentrate the sound inside themselves, without amplifying it and without closing the external auditory canal.