urbanLab Magazin 2021 - Transformation

Fig. 2: The water feartures and their spectrum
at the Sheaf Square, Sheffield, UK.
SPACE
In urban open public spaces, architectural
changes and urban design options
could affect the sound field significantly.
A study in a typical urban square
(Kang, 2005) shows that if a relatively
far field is considered, the sound pressure
level (SPL) is typically 6-9dB lower
when the square side is doubled;
8dB lower when the square height is
decreased from 50m to 6m (diffuse
boundaries); 5dB (diffuse boundaries)
or 2dB (geometrical boundaries) lower
if the length/width ratio is increased
from 1 to 4, and 10-12dB lower if the
boundary absorption coefficient is increased
from 0.1 to 0.9. Whilst these
results show the effectiveness of controlling
the geometry and boundary
conditions for soundscape planning
and design, other landscape elements
may be effective too, such as vegetation,
urban furniture and barriers.
Reverberation is also an important index
for the soundscape in urban open
public spaces. On the one hand, with a
constant SPL, soundscape evaluation
may vary with different reverberations.
On the other hand, a suitable reverberation
time (RT), say 1-2s, can make
street-music more enjoyable.
PEOPLE
Considerable research has been carried
out in terms of the effects on the
soundscape evaluation (Yu and Kang,
2008) by various (1) social and demographic
factors, including age, gender,
education, profession, residential status
(i.e. local and non-local), cultural
background, and acoustic environment
at home and at working place; (2) activities
including moving types such as walking,
playing with children, and sport;
and non-moving types such as sitting,
standing, reading, and watching; and (3)
behaviours such as wearing earphones
and sunglasses. The results have clearly
58 HUMAN CENTERED DESIGN