Benefits of using ANSI/ASA S12.9 -2020/Part 7: “Measurement of environmental sound: Measurement of low-frequency noise and infrasound outdoors and in the presence of wind and indoors in occupied spaces.”

I was invited and honored by Dr. Paul Schomer to Chair working group S12/WG 54 for Part 7 of ANSI S12.9. The working group had 23 learned members all at the reasonable disposal of the Chair. At the start I knew the technical tasks that would have to be done and it would be a time-consuming process, at least a year; completion took over three years. Some of the fundamental tasks required were (a) Define and quantify wind-induced-noise (WIN) for standard wind screen measurements and with upgraded wind protection to lower WIN, (b) Define conversion corrections necessary between post-mounted above grade and ground plane mounted microphones, and (c) Define a repeatable technique for measuring pressure levels outside and inside structures to characterize noise reduction NR in 1/3 octave bands for the facade of the structure. These tasks were completed with much effort by numerous group members. The standard may be consulted for analyses and reference, particularly Annexes A through D, as well as for authoritarian standard purposes. This presentation will outline the many valuable procedures in the standard for measuring low frequency noise and infrasound.