Soundscape and Landscape Ecology - Soundscape Ecology: Principles, Patterns, Methods and Applications - page 13

time, characterizing the sonic ambience. Often the intensity of the background
noise can be masked by foreground sounds, but they represent the sonic landmarks
that can be actively discriminated by organisms to fix their home range without
using visual cues or integrating them. For instance, the background sound from
coral reefs can orient pelagic fishes, in the same manner that the traffic of a highway
can discourage birds and mammals from crossing the area, reducing the risk of
collisions with vehicles.
The landscape approach, which presently is so popular for investigating the role
of land use policies to preserve the biodiversity or to evaluate the effects of human
intrusion by logistic infrastructures and urban development, often cannot allow
detection of most of the processes that occur at a short time scale of hours or days.
For instance, close to human settlements, as in urban areas, some hours of the
day are full of background noise and high intense foreground sound (sirens, horns,
jackhammers, loud human voices, music) in the middle of the morning and during
the evening.
For this reason, integration with a soundscape investigation approach allows
exploring short-term dynamics that have a great impact on the ecological and
behavioral processes that occur at the population and community scale.
It is recognized that visual and acoustic stimuli are strictly connected during the
perception of the environment. In their investigation, Carles et al. ( 1999 ) have
found that in urban green spaces and in cultural landscapes the sound environment
is essential to complete environmental evaluation. The information from a land-
scape often does not provide sufficient cues for animals such as humans, and the
acoustic component become increasingly important with the use of cognitive
sensing. The soundscape can be considered an additional layer of spatial informa-
tion across a landscape.
Foreground sound strongly concurs with animal behavior, to animal displace-
ment in time and space, and this effect has been explained by Farina et al. ( 2011a )
as a soundtope when produced by a local community of acoustic animals.
Foreground sound, for its dynamic characteristics, triggers reactions in animals,
and humans also seem more independent by the structure of land use and land
cover. Foreground sounds become an information structure that has a relevant role
in shaping local acoustic communities.
1.8 Hi-Fi and Lo-Fi Soundscapes
If the distinction between sound and noise is quite simple, it is not so easy to define
a high-fidelity soundscape and a low-fidelity soundscape.
In the first case we have a soundscape in which every component is distinctly
heard without significant effects of masking, but in the second case the overlap is so
important that we have difficulties in distinguishing the individual sounds.
These two characteristics are not necessarily associated with noise or acoustic
pollution. Along a mountain stream, the sound of the flowing water reduces the