Traffic noise is one of the most daunting environmental problems in cities. However, urban planners and architects fail to give attention to this problem. This dissertation contributes to bridge the gap between architecture and acoustics. Three different approaches were used to find architectonic guidelines to improve urban sound quality. 1) Reducing road traffic noise through the modifications of a standard street canyon shape. The sound distribution in more than 70 cases was numerically studied with the full-wave finite-difference time-domain method (FDTD). Certain street configurations strongly reduce the overall traffic noise levels for pedestrians and on building façades. 2) Considering people´s perception of the urban environment and the influence of audio-visual perception. An innovative method was proposed to compare the quality of different urban designs using Virtual Reality technology. The acoustic and visual elements were also assessed. 3) Evaluating the personal differences between individuals to guarantee pleasurable urban spaces for all types of people. The outcomes of this research are presented as guidelines for urban planners and architects to improve the quality of the urban sound environment. An approach to the implementation of the Urban Sound Planning within a smart urbanism is also provided.