From the summary of FAA-2003-15230, "The FAA is soliciting technical information from other Federal agencies, industries, universities, and other interested parties on the mitigation of sonic boom from supersonic aircraft. The FAA is trying to determine whether there is sufficient new data supported by flight over land. This document solicits information on the latest research and development activities directed at mitigating sonic boom. The FAA may use this information of future rulemaking actions."
The complete solicitation and responses from
Gulfstream, Lockheed Martin, Boeing, Pratt & Whitney and others can be viewed
by doing a docket search for number 15230 at http://dms.dot.gov/search/searchFormSimple.cfm.
The responses detail many advances in sonic boom mitigation technology and urge
the FAA to consider regulatory changes wherever sonic boom can be proven to
be acceptably quiet.