Volume 129, Issue 3, March 2011
Index of content:
- NOISE: ITS EFFECTS AND CONTROL 
129(2011); http://dx.doi.org/10.1121/1.3531803View Description Hide Description
Noise impacts resources and visitor experience in many protected natural areas, and visitors can be the dominant source of noise. This experimental study tested the efficacy and acceptability of signs asking visitors to be quiet at Muir Woods National Monument, California. Signs declaring a “quiet zone” (at the park’s Cathedral Grove) or a “quiet day” (throughout the park) were posted on a randomized schedule that included control days (no signs). Visitor surveys were conducted to measure the cognitive and behavioral responses of visitors to the signs and test the acceptability of these management practices to visitors. Visitors were highly supportive of these management practices and reported that they consciously limited the amount of noise they produced. Sound level measurements showed substantial decreases on days when signs were posted.
The Norwegian Façade Insulation Study: The efficacy of façade insulation in reducing noise annoyance due to road traffic129(2011); http://dx.doi.org/10.1121/1.3533740View Description Hide Description
The efficacy of façade insulation in providing an improved indoor noise environment and in reducing indoor noise annoyance was examined in a socio-acoustic before-and-after study with a control group. An average equivalent noise reduction inside the dwellings of 7 dB was obtained from the façade insulation. Whereas 42% of the respondents were highly annoyed in the before-situation, this dropped to 16% in the after study. The conclusion is therefore that the façade insulation provided a substantial improvement in the indoor noise environment. The advantage with respect to indoor noise annoyance, of having the bedroom facing the least noise-exposed side of the dwelling corresponded to a 6 dB noise reduction. The changes in annoyance from noise reduction due to the façade insulation were in accordance with what would be expected from the exposure-response curves obtained in the before-situation. A total of 637 respondents participated in the before-study. Of these, 415 also participated in the after study. Indoor and outdoor noise exposure calculations for each of the dwellings were undertaken before and after the façade insulation was implemented.