Volume 126, Issue 1, July 2009
Index of content:
- NOISE: ITS EFFECTS AND CONTROL 
126(2009); http://dx.doi.org/10.1121/1.3148193View Description Hide Description
To select an appropriate standard floor impact source to simulate real floor impacts, objective and subjective evaluations of the floor impactsounds were conducted in a box-frame-type structure with reinforced concrete slab floors. The sounds simulated in the test were those that would result from an adult walking barefoot, children running and jumping (represented by a heavy-weight impact source, such as a bang machine or an impact ball), as well as those of a person walking in high-heels or a lightweight object being dropped (represented by a tapping machine). Similarity tests between human-made impactsounds and standard heavy-weight impactsounds were performed. Sound quality (SQ) metrics were used to predict the results of the similarity tests. These results showed that the impactsound of an impact ball is more similar to a human-made impactsound than the sound of a bang machine. A multiple regression analysis showed that loudness and roughness are significant factors describing the results of similarity judgment among SQ metrics. Much of the data from the standard impact sources, measured in reinforced concrete floors with rigid floor coverings, have been collected. An empirical relationship was established to convert the impactpressuresound level from the bang machine or tapping machine to that from the impact ball. This study indicates that the use of an impact ball is reliable for simulating human impactsounds.
126(2009); http://dx.doi.org/10.1121/1.3147491View Description Hide Description
A ray-based method is presented for evaluating multiple acoustic diffraction by separate rigid and parallel wide barriers, where two or more neighboring ones are of equal height. Based on the geometrical theory of diffraction and extended from the exact boundary solution for a rigid wedge, the proposed method is able to determine the multiple diffraction along arbitrary directions or at arbitrary receiver locations around the diffracting edges, including the positions along the shadow or reflection boundaries or very close to the edges. Comparisons between the results of the numerical simulations and the boundary element method show validity of the proposed method.
126(2009); http://dx.doi.org/10.1121/1.3147510View Description Hide Description
Curvilinear effects of age on self-reported annoyance from environmental noise were investigated in a pooled international and a Dutch sample of in total 62,983 individuals aged between 15 and . All respondents were frequently exposed to varying levels of transportation noise (i.e., aircraft, road traffic, and railway noise). Results reveal an inverted U-shaped pattern, where the largest number of highly annoyed individuals was found in the middle-aged segment of the sample (peaking around ) while the lowest number was found in the youngest and oldest age segments. This pattern was independent of noise exposure level and self-reported noise sensitivity. The inverted U-shape explains the absence of linear age effects in previous studies. The results are discussed in light of theories predicting an age-related vulnerability to noise.
Policy discourse, people’s internal frames, and declared aircraft noise annoyance: An application of Q-methodology126(2009); http://dx.doi.org/10.1121/1.3139904View Description Hide Description
Aircraft noise annoyance is studied extensively, but often without an explicit theoretical framework. In this article, a social approach for noise annoyance is proposed. The idea that aircraft noise is meaningful to people within a socially produced discourse is assumed and tested. More particularly, it is expected that the noisepolicy discourse influences people’s assessment of aircraft noise. To this end, Q-methodology is used, which, to the best of the authors’ knowledge, has not been used for aircraft noise annoyance so far. Through factor analysis five distinct frames are revealed: “Long live aviation!,” “aviation: an ecological threat,” “aviation and the environment: a solvable problem,” “aircraft noise: not a problem,” and “aviation: a local problem.” It is shown that the former three frames are clearly related to the policy discourse. Based on this observation it is argued that policy making is a possible mechanism through which the sound of aircraft is turned into annoyance. In addition, it is concluded that the experience of aircraft noise and, in particular, noise annoyance is part of coherent frames of mind, which consist of mutually reinforcing positions and include non-acoustical factors.