It may be possible to build supersonic aircraft that produce low-level sonic “booms”, but even if they are much quieter than their more traditional counterparts, how acceptable would these be, and how does the impact relate to that of other transient environmental sounds? It is likely that the louder the transient, the more annoying or disturbing it is, but when the loudness varies significantly throughout the event, how should event loudness (a single number) be determined from a sound recording? The rapid rise of loudness may also evoke a startle response. Many environmental transient noise events also have high levels of low frequency energy which can propagate through building structures with little attenuation. The use of statistics of the predictions from a time-varying loudness model, developed by Glasberg and Moore, to predict loudness and startle was investigated. This model was investigated because it incorporates models of the temporal behavior of the human hearing system, clearly of importance with rapidly changing sounds, and it is claimed that it models the response to low frequency noise better than other loudness models. The impact of sonic boom shape changes on the estimated time-varying loudness was investigated, as was their impact on the output of an annoyance and a startle model developed from prior research.
展开▼
