Intelligent Noise Mapping for Smart Cities: Solutions, Trends, and Research Opportunities

Noise pollution is an often-overlooked environmental threat that poses a concealed but severe risk to public health and urban ecological environment. Despite being invisible, noise has become the second-largest environmental factor contributing to public health issues. Furthermore, noise pollution hinders the sustainable development of cities. To manage noise pollution in urban areas, intelligent noise mapping is expected to be an essential tool that can transform invisible noise problems into visible ones and provide an efficient governance basis. However, this technological approach is still in its infancy, and there is a significant gap in implementing large-scale dynamic urban noise mapping. In this article, we provide a critical review of recent advances in intelligent noise mapping, analyzing their technical principles, fundamental research topics, advantages, and limitations. We also present our insights on the development trends of intelligent noise mapping for smart cities. Finally, we identify four critical open issues and discuss our insights to address these gaps for future research. This study's findings can contribute to the development of more effective solutions to address noise pollution and promote sustainable smart cities.

Introduction

Urbanization drives global city growth, with over 50% of the world's population now residing in cities, a figure projected to reach 68% by 2050. It brings economic opportunities, better infrastructure, and enhanced lives. However, it also brings ecological challenges, notably pollution. High population density and human activities increase emissions, causing air, water, and often overlooked noise pollution. Noise, ranked second by World Health Organization after air pollution, poses significant health risks, including cardio-vascular issues, sleep disturbances, and cognitive impairment. Moreover, noise pollution harms ecosystems, impeding urban sustainability [1].