Active noise controlActive noise control (ANC), also known as noise cancellation (NC), or active noise reduction (ANR), is a method for reducing unwanted sound by the addition of a second sound specifically designed to cancel the first. The concept was first developed in the late 1930s; later developmental work that began in the 1950s eventually resulted in commercial airline headsets with the technology becoming available in the late 1980s. The technology is also used in road vehicles, mobile telephones, earbuds, and headphones.
Wireless access pointIn computer networking, a wireless access point, or more generally just access point (AP), is a networking hardware device that allows other Wi-Fi devices to connect to a wired network. As a standalone device, the AP may have a wired connection to a router, but, in a wireless router, it can also be an integral component of the router itself. An AP is differentiated from a hotspot which is a physical location where Wi-Fi access is available.
Political hip hopPolitical hip hop is a subgenre of hip hop music that was developed in the 1980s as a way of turning hip hop into a form of political activism. Political hip-hop generally uses the medium of hip hop music to comment on sociopolitical issues and send political messages to inspire action, create social change, or to convince the listener of a particular worldview. It was inspired partially by politically-focused 1970s artists such as The Last Poets and Gil Scott-Heron, as well as the Black Power movement and revolutionary politics of the 1960s and 1970s.
