Peter Laurits Jensen (16 May 1886 – 26 October 1961) was a Danish American engineer, inventor and entrepreneur.
He was employed as engineer by the Federal Telegraph Company in California, which purchased the Poulsen patent, until November 1910.
[4] In 1911, he co-founded with Edwin S. Pridham (1881–1963) the Commercial Wireless and Development Co. in Napa, California, utilizing the financial backing of Richard O'Conner and the engineering assistance of master mechanic Carl Albertus.
Made the first public address system and used on Christmas Eve in 1915 in San Francisco at a gathering where 75,000 people were present and who heard distinctly all the speeches and announcements.
He also invented and patented, with Edwin S. Pridham, the first anti-noise self-neutralizing microphone in 1917 which allowed wireless communication between aircraft and the ground.
He was elected an Extraordinary Member of the Danish Engineering Society, and knighted by the King of Denmark in the Order of the Dannebrog.