Old Lyme, CT - Apr 18, 2002 - Electroacoustical engineer Prof. Dr. Fritz Sennheiser celebrates his 90th birthday on May 9, 2002. As founder of Sennheiser Electronic GmbH, he brought many of the audio industry's watershed products to market, including the radio standard MD 2 and MD 21 microphones, the shotgun microphone (MD 82), the Mikroport wireless microphone system in 1958, the HD 414 open headphones, infrared transmission technology such as the HiDyn RF noise reduction, and DVD-quality microphone technology (MKH 800: 20Hz - 50,000kHz).