Robert Alex Baron was awakened one morning in 1964 by the ear-shatting cacophony of subway construction in the street below his Manhattan apartment. In a sense he hasn't slept since. Giving up a career as a successful theater manager, he has devoted his time to learning all he can about noise and its control, and passing the information on to others. Head of a leading anti-noise organization, Citizens for a Quieter City, he has appeared as an expert witness before Congressional committees has given lectures on noise control throughout Europe and the United States.