Established in 1945 in Wedemark, Germany, Sennheiser is a world leader in microphone technology, RF-wireless and infrared sound transmission, headphone transducer technology, and most recently, in the development of active noise-cancellation.

Sennheiser Electronic Corporation (SEC) is the U.S. wholly-owned subsidiary, with headquarters in Old Lyme, Connecticut. SEC represents all Sennheiser products in the United States. It distributes a variety of other pro audio lines, including Neumann, Turbosound, HHB, K+H, Rosendahl and Australian Monitor. The company's production facilities are found in Burgdorf, Germany, Tullamore, Ireland, and Albuquerque, New Mexico .

The company was founded in 1945 by Professor Dr. Fritz Sennheiser (b. 1912). In 1982 he handed the management over to his son, Jörg Sennheiser. Since 1991, Jörg Sennheiser has been honorary professor and has held lectures on electroacoustics at the University of Hanover since 1981.