Impact of low frequency road traffic noise on indoor environments for different facade structures
Ladda ner
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Sound and vibration (MPSOV), MSc
Publicerad
2022
Författare
Rashed, Lauk
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Road traffic noise is a major environmental problem in Europe where at least 20
percent of the EU population live in areas where traffic noise levels are harmful
to health. Recent changes and regulations in Swedish law enables a higher sound
pressure level at facade, making it easier to build closer to roads. Typical noise reduction
measures improve sound insulation at mid and high frequencies well, while
not being as effective at lower frequencies of 20–200 Hz. As a consequence, more
low frequency traffic noise indoors can be expected as we build closer to trafficked
streets. This thesis aims to investigate the effect of low frequency traffic noise inside
dwellings where (1) a study of traffic modelling and field measurements on a selection
of different facade structures is made to determine the indoor low frequency
traffic noise and (2) a psychoacoustic study is carried out where the annoyance level
from low frequency traffic noise is investigated through listening tests.
The measurements suggest that none of the studied apartments have good insulation
for low frequency noise. For all of the studied facades, peak pass by sound levels
due to heavy vehicles are above our audible threshold and also at certain frequencies
above the recommended Swedish guidelines for indoor low frequency equivalent
levels.
The listening test suggests that the largest annoyance for inhabitants inside dwellings
comes from heavy vehicles while light vehicles pose no greater annoyance even if the
peaks of the low frequency sound levels inside the dwelling are above the equivalent
level guideline values. Furthermore, the listening test results suggest that the annoyance
that inhabitants experience is not only from low frequency components from
vehicles passing by at a constant speed with no significant tonal changes. Instead
they suggest that the low frequency components constitute the annoying part when
there are clear tonal changes such as in situations with accelerating vehicles.
Beskrivning
Ämne/nyckelord
building acoustics, urban acoustics, psychoacoustics, low frequency noise, facade insulation, Nord2000, CNOSSOS