Summary of recent NASA studies of human response to sonic booms

TLDR

NASA Langley Research Center has conducted laboratory, in‑home, and field studies on human responses to sonic booms. The laboratory studies aimed to quantify loudness and annoyance responses to varied sonic boom signatures and evaluate noise descriptors as estimators of subjective effects. A high‑fidelity sonic boom simulator generated and played user‑prescribed and recorded waveforms to test subjects in laboratory and in‑home settings, while field studies were conducted in real environments. Waveform shaping markedly reduced loudness and annoyance, with perceived level the best predictor; asymmetrical waveforms were quieter than symmetrical ones at equal perceived level, ground‑reflected waveforms were fully explained by perceived level, the equal‑energy theory of annoyance applied to multiple exposures, and field studies showed sonic‑boom annoyance exceeded that of conventional aircraft noise at comparable continuous equivalent noise exposure.

Abstract

NASA Langley Research Center has conducted three groups of studies on human response to sonic booms: laboratory, “inhome,” and field. The laboratory studies were designed to: (1) quantify loudness and annoyance response to a wide range of shaped sonic boom signatures and (2) assess several noise descriptors as estimators of sonic boom subjective effects. The studies were conducted using a sonic boom simulator capable of generating and playing, with high fidelity, both user-prescribed and recorded boom waveforms to test subjects. Results showed that sonic boom waveform shaping provided substantial reductions in loudness and annoyance and that perceived level was the best estimator of subjective effects. Booms having asymmetrical waveforms were found to be less loud than symmetrical waveforms of equivalent perceived level. Subjective responses to simulated ground-reflected waveforms were fully accounted for by perceived level. The inhome study presented participants with simulated sonic booms played within their normal home environment. The results showed that the equal energy theory of annoyance applied to a variety of multiple sonic boom exposures. The field studies concluded that sonic boom annoyance is greater than that in a conventional aircraft noise environment with the same continuous equivalent noise exposure.