English abstract
Roadways in major cities have increased nowadays due to rapid growth in population and
usage of vehicles thereby resulting into several environmental problems including noise
pollution. The aim of this research is to investigate and assess vehicular noise pollution
levels in Muscat governorate, the capital of the Sultanate of Oman. Vehicular sound
pressure levels were measured in various Wilayat/regions in Muscat Governorate to define
existing noise exposure levels. The measurements carried out in 2018 with Noise Sensor
type MK:427. The measured sound levels were modeled and validated for prediction
through Artificial Neural Network (ANN) using MATLAB. Traffic counts were used as
input data along with meteorological factors. The traffic counts were provided by Muscat
Municipality while meteorological factors were measured by the air pointer instrument.
The attitudes toward noise pollution and perceived annoyance impact were assessed based
on survey through questionnaire distributed among 470 residents exposed to the traffic
noise. The percentage of highly annoyed persons was calculated according to the dose response model established by World Health Organization (WHO). The results of this
study showed that, the traffic noise levels in Muscat were found to be acceptable during
day time with an average of 60-61 dB and exceeding the Ministry of Environment and
Climate Affairs (MECA)(55 dB), the Environmental Protection Agency (EPA)(50 dB)
and WHO (45 dB) recommended noise level at night. Pearson correlation analysis resulted
in a weak correlation between meteorological variables and measured noise levels (r value
ranged between -0.4 to 0.3). On the other hand, stronger relationships (r = 0.8) were found
between traffic count and measured noise in some locations. Generally, the ANN model
showed good traffic noise prediction with maximum and minimum Root Mean Square
Error (RMSE) value of 1.7- 0.17 dB, respectively. According to the survey results, about
of 91.7 % of the respondents found traffic noise at home as source of annoyance.
Moreover, about 50% of the respondents reported moderate to high prevalence of
perceived annoyance. Finally, a set of recommendations is presented to reduce traffic
noise problem in Muscat Governorate.
