Knowles Corp. supplies advanced micro-acoustic, audio processing, and precision device solutions. It operates through Audio and Precision Devices segments. Read More The Audio segment includes analog and digital micro-electro-mechanical systems microphones, electret condenser microphones, smart microphones, ultrasonic sensors, acoustic processors, and balanced armature speakers. The Precision Devices segment offers multi-layer ceramic capacitors, electromagnetic interference filters, high reliability capacitors, single layer capacitors, precision variable capacitors, and thin film devices across diverse end markets, such as industrial, defense, aerospace, medical, and telecommunications markets. The company was founded by Hugh Knowles in 1946 and is headquartered in Itasca, IL.