The company was founded in 1945, just a few weeks after the end of World War II, by Fritz and seven fellow engineers of the University of Hannover in a laboratory called Laboratorium Wennebostel. The laboratory was named after the village of Wennebostel in the municipality of Wedemark to where it had been moved due to the war. Its first product was a voltmeter. Lab W began building microphones in 1946 with the DM1, and began developing them in 1947 with the DM2. By 1955, the company had 250 employees, and had begun production of many products including geophysical equipment, the Noise-Compensated microphone (DM4), microphone transformers, mixers, and miniature magnetic headphones.
In 1968, Sennheiser released the world's first open headphones. The introduction of open headphones affected the headphone market as they were able to produce a more natural sound that many users preferred.
It was transformed into a limited partnership (KG) in 1973. In 1980, the company entered the aviation market, supplying Lufthansa with headsets.
The company began producing modern wireless microphones in 1982, the same year when founder Fritz handed the management of the company over to his son, Jörg . In 1987, Sennheiser was awarded at the 59th Academy Awards for its MKH 816 shotgun microphone.
In 1996, Sennheiser received an Emmy Award for its advancements in RF wireless technology. Also in 1996, Sennheiser became a private limited company (GmbH and Co. KG). Dr. Fritz Sennheiser died in 2010.
On July 1, 2013, Daniel and Andreas were promoted to the position of CEO responsible for Sennheiser electronic GmbH & Co. KG.