Acoustics pioneer Amar Bose, founder and chairman of the audio technology company Bose Corp., known for the rich sound of its small tabletop radios and its noise-canceling headphones popular among frequent fliers, has died at age 83. Bose's death was announced Friday by the company's president, Bob Maresca, and the Massachusetts Institute of Technology, where Bose began his acoustics research and was on the faculty for more than 40 years.