American Signal Corporation (ASC) is an outdoor warning siren and mass notification company in the United States. ASC was founded in 1942 as Biersach and Niedermeyer (B&N). After performing poorly, the company reformed as The Alerting Communicators of America (ACA) in 1967 and expanded the line of warning systems they produced. In 1992, ACA went bankrupt and was bought and reformed as the American Signal Corporation.