This introduction to the second part of the Sonic‐Boom Symposium reviews the history of observations on human reactions to the sonic boom from the time when the boom was a demonstration curiosity to the present day where reaction of the population to the sonic boom is a scientific problem of technical, economic, social, and political consequences at the national and international level. The field programs conducted by the USAF and NASA over the last 15 years and over the last 5 years by the FAA were all of limited scope with respect to exploring direct and indirect physiological and psychological human reactions to sonic booms of different intensity and exposure frequency. Although the data accumulated might be adequate to decide on preliminary stopgap exposure criteria, it is obvious that a broader approach to the problem is required. Laboratory work in support of these questions has hardly been started. Neither conventional acoustic and vibration generators for boom‐type stimulation nor special equipment for high‐fidelity sonic‐boom simulation have been fully utilized. Some of the open questions and possible approaches are discussed as part of a broad, long‐range research program required to come up with scientific data as bases for operational sonic‐boom exposure criteria.