Microphone headsets employ a set of earphones fitted with a microphone on a swing arm that places the pickup around the mouth. These devices aid in a number of purposes, such as online chatting, recording speech, and operating telephones. They are fitted with jacks or port cables for use in their host system, usually a computer or telephone. Types can be categorized by purpose and technology. There are headsets for computers, broadcasting, and conferencing, as well as wired, wireless, and directional differences.
Wired and wireless varieties are designed to function with a personal computer (PC). Wired types input via separate cables for earpiece and microphone, or with a single universal serial bus (USB) jack. Wireless varieties offer hands-free mobility, but at a cost of battery power.
Omnidirectional microphones pick up sounds from every direction. Unidirectional types aim toward the speaker and eliminate unwanted background noises, such as chatter, keyboard, or paper sounds. Typically, unidirectional microphone headsets focus more on the speaker's voice and not on other voices or ambient sounds, compared with omnidirectionals.
Computer users rely on microphone headsets for video or audio conferencing; casual use doesn't require much noise cancellation from the earphones or ear cups. Sets might eliminate output from external computer speakers re-entering the microphone and causing echoes. Operator sets are more enclosed from ambient noise and may provide a windscreen on the microphone to reduce the noise from plosive syllables like P or B sounds. These varieties often mix in sideband; that is, they amplify the speaker's voice through the set to compensate for the muffling effect of the ear cups.
Broadcast-quality microphone headsets are often outfitted with two-way radio systems for use in professional sound studios or stages. They sometimes have only one ear cup in order to allow the user to be more aware of his surroundings. Performers often employ lightweight stage and conference headsets fitted with radio transmitters. These devices clip on the ear and extend a small boom toward the mouth.
Other microphone headsets are specially designed for noisy environments. Specially equipped models can minimize ambient sounds by detecting them and applying anti-phase filtering, or by clipping peak interferences. These types serve in airports or military environments. Regardless of purpose or technology, headset microphones generally employ analog or digital conversion of sound waves via sensor to electronic signals, and the earphones reverse the process, converting electronic signals back to audible sound waves.