Noise pollution is a major issue in unplanned metropolitan areas, especially in Asia. It can negatively affect human health and well-being. This study investigates noise pollution in an urban area in India. The researchers aimed to identify noisy areas and times and potential sources of noise. A field measurement approach has been adopted to gather noise exposure level data from North 24 Paraganas and Kolkata pockets. To test the noise levels, 58 locations have been chosen near significant intersections for two weeks. A field survey was carried out in the mornings (6–7 AM), at midday (11–1 PM), in the afternoons (3–5 PM), and in the evenings (8–10 PM) from April to August 2022. The simple random sampling method was used and locations were demarcated by trilateration method with GPS. Collected data was mapped out utilizing ArcMap 10.3.1 programming. Two sample paired t-tests were used to analyse the spatio-temporal noise intensity variation. Noise levels were highest between 11 AM and 1 PM, likely due to traffic and commercial activity. Wards 11, 12, 13, and 20 in Kolkata experience the most noise throughout the day. Areas with lower noise levels include Kamarhati and Baranagar municipalities. Weekends generally had lower noise levels than weekdays. The study suggested several possible sources of noise pollution, including traffic, honking, markets, religious activities (amplifiers in temples and mosques), and activities of street vendors. The study ultimately provides a noise dissimilitude map of the study area which can be a templet to find source of noise pollution for other areas also.