Sonic Boom Reporting
NASA seeks to reliably measure people's reactions to sonic booms. But reactions can be hard to recall accurately if the interviews occur long after the noise events. We proposed a method of interviewing people in real-time using smartphones, and organized and conducted a successful pilot study.
49 residents of Edwards Air Force Base were given Android smartphones. They were asked to push a large red "button" displayed on the home screen of the phone whenever they noticed a sonic boom, and to complete a brief interview administered by the phone. They were also asked to answer several questions at the end of each day.
Interview information collected by the phones was transmitted automatically, via mobile wireless network, to databases in cloud-based servers. The phones also regularly reported their "health" (battery charge, available memory, location, connectivity, etc.) to the servers. The databases were immediately available (password-protected and stripped of user-identity information) to analysts via the Internet.
For two weeks, the test subjects were exposed to 90 low-amplitude sonic booms intentionally produced by NASA F-18 flights. The participants made 1,717 sonic boom reports from home, indoors, where sound level doses could reasonably be estimated.
Some degree of annoyance was indicated in 24% of the reports, with "high" ("very" or "extremely") annoyance in 5%. Test participants described themselves as "startled" in 29%. Noticeable "rattle" was reported in 49%. Not surprisingly, the intensity of reactions to booms generally increased with increasing boom levels.
The study showed that our method improved the precision, immediacy, and cost-effectiveness of field assessments. The method allows adaptive study designs, so a wider range of analyses can be conducted. Real-time data collection and the availability of situational information about the circumstances of interviewing offer novel opportunities for fine-grained analyses. Preparations for a large-scale experiment are under way.
I contributed to the study design and execution, created the system architecture, and developed the mobile apps and server software.
Here are the screens shown by the key "Report Boom" Android app:
