Within weeks, there were complaints from residents concerned about hearing sound from rock shows such as Julian Lennon and the Moody Blues. CTA responded immediately by setting up sound monitors to analyze sound levels during almost every show from the 1986 season. Working closely with Richard Cann of Grozier Technical Systems , the first concert sound management system was installed for the 1987 season. The Grozier System provides continuous monitoring of sound levels, before, during, and after each show. A printed hard copy provides permanent records for cross-checking complaints, and enforcing the sound level exceedance clause in the talent contract.
Similar systems are now in use at many outdoor concert venues across the country.
CTA has provided consultation on concert facility planning and permitting, and concert sound mitigation for projects in Phoenix AZ, St. Paul MN, Columbus OH, Palm Beach, FL, and Hong Kong. In 1993 CTA was contacted by the office of William Lemessurier, structural engineer, to advise on feelable vibration in a new building under construction. Persons standing on this part of the floor felt significant vibration whenever someone walked on the bridge portion of the structure. There was absolutely no danger of collapse, but the owner felt the vibration would be distracting to visitors. After some calculations to model the effects of adding steel to stiffen the structure, we suggested a tuned-mass damper to control the oscillation of the structure.