Applications - Soundscape Ecology: Principles, Patterns, Methods and Applications - page 279

overflights enter in direct conflict with the conservation goals. Severe consequences
on wild fauna result, and a recent case was documented in a sky resort not far from
Cortina d'Ampezzo (Italy) during the 2013 New Year of a brown bear that was
probably awakened from its hibernation by fireworks.
Legislation when restrictive can create severe consequences both on the eco-
nomic and on leisure and recreational offers. In a study conducted in the Grand
Canyon National Parks, an air tour flying over Las Vegas has been estimated to
contribute $504 million to the economy of southern Nevada, and restriction of such
overflights would cut $249 million.
Noise is an ambient stressor. Landscape assessment is conducted using both
visual and acoustic cues. Many researchers have demonstrated that people are
escaping urban noise and as this is a priority for visitors of national parks, techno-
logical sounds in those conditions are considered highly negative, nonappropriate,
and impacting. Motives (escaping urban noise) and expectations (natural sounds and
quiet areas) are the two elements that drive the landscape assessment of park visitors.
In evaluating the effect of noise on landscape assessment, Mace et al. 1999 found
that a airplane noise from 40 to 80 dB(A) was rated negative in landscape assess-
ment. Other impacted sounds can decrease the rate as well.
Aircraft overflight noise produced by helicopter tours is frequently encountered
in national parks such as Grand Canyon, Hawaii Volcanoes, Haleakala, and Bryce
Canyon. Noise is considered an environmental stressor co-responsible with other
disturbing sources to several physiological and psychological effects that can
impair individual well-being for a long time. Although helicopters are associated
with rescue activity and should not produce a hostile feeling, an experiment in
which were utilized 200 undergraduates Mace et al. ( 2003 ) found that 60 dB (A)
noise from a helicopter decreased the ratings of scenic beauty, solitude, tranquility,
freedom, naturalness, and preference, and higher ratings of annoyance in every type
of scenic context administrated.
ThecasereportedbyBowlbyeta .( 1990 ) about the impact of noise
produced by the activity of the local airport (Jackson Hole) on Grand Teton
National Park quietness explains very well that monitoring the noise and
appropriate regulations can improve the sonic environment. This study showed
that the dose of noise for the year is not significant although a small difference
appears between summer and winter; in winter, more noise was observed.
Compliance was observed with the day-night level limit except when the
wind direction requires departure of aircraft in the northern direction; then
day-night level is not respected and is sanctioned. The new models of aircraft
can solve in part the problem of preserving quietness in this remote area. When
no aircraft are in flight this area is very quiet and so a distant airplane is
sufficient to create an annoying event even far from the airport, an example
of the relativity of sonic environment perception.