Sonic Patterns I: The Noise - Soundscape Ecology: Principles, Patterns, Methods and Applications - page 172

only physical parameters such as frequency and sound pressure level but also
psychoacoustics parameters such as loudness, sharpness, roughness, fluctuation
strength, the informative content of the sound signal, and a cultural filter.
Noisiness and annoyance are subjective attributes of perceived sound, and
definitively the social and cultural background are important more than the energy
of sound. Thus, noise evaluation depends on the physical characters of the sound,
the psycho-acoustical features of the human ear, and simultaneously the psycho-
logical and social aspects of a human being. Human sensation and psychoacoustic
parameters are connected by complex interactions, and manipulating sounds is a
premise for design and managing sounds indoor and outdoors also.
Noise annoyance that represents a so strategic and relevant issue can actually be
mapped using the A-weighted sound pressure level, but this metric does not
reflect all the complexity of the soundscape domain (Genuit and Fiebig 2005 ).
The appreciation of annoyance requires characterization of the sound, its time
structure, and finally the attitude and expectation of the listener. Annoyance that
is considered the overall evaluation of the disturbance and the unpleasantness of
environmental noise remain highly subjective, linked to social and cultural
backgrounds. Finally, annoyance and all the effects of noise on human life (but
also on animal life) cannot be simply described by a few physical parameters.
In this direction is addressed the psychoacoustics approach and methodologies that
considers other aspects beyond the physical sonic components, such as context,
kind of information, individual expectation, and attitude to the sound.
Unfortunately, masking effect, sound impression, spatial distribution, and com-
plex phase relationships are factors that limit the conventional one-channel
measurements. Binaural technology seems to solve such limits. Binaural reproduc-
tion allows the listener to be in approximately in the same condition where the
sound occurred in the living sonic environment. The use of binaural recording for
reproducing a sonic environment in psychoacoustic tests is very effective. Spectral
band and time integration are two possible parameters that when changed produce a
different reply to annoyance.
Conventional noise maps based only on the sound pressure level A (averaged) do
not describe completely the environmental noise quality and complexity. The
adoption of binaural technique improves the capacity to record more realistic
sonic patterns useful for formulating, after a post-processing, the level of annoy-
ance of listeners.
6.22 Noise from Urban Soundscapes
Urban can be defined any area of high-density human population and human-built
structures in which the noise produced by human machines creates an unrivaled
effect that cannot be found in the natural world (Warren et al. 2006 ). Sound in urban
areas can originate from traffic sounds, mechanical sounds, human sounds, and
natural sounds.