Method Sensitivity in Façade-Based Traffic Noise Exposure and Health-Burden Assessment in Quito

Strategic noise maps represent a valuable tool for the characterisation of urban soundscapes, but their transformation into indicators related to the exposed population and health effects remains a matter of methodology, particularly in the absence of dwelling-level information. A workflow at the façade level for the estimation of population exposure to road-traffic noise and high sleep disturbance in six sampled sectors of Quito, Ecuador, is developed and tested. The workflow combines outputs from strategic noise maps, cadastral and land-use data, population of census sectors, receiver levels on façades, and three alternative methods of population assignment consistent with CNOSSOS-EU. Sectors were also classified by urban–methodological complexity to assess whether the sensitivity of exposure estimates varies across urban fabrics. The results show that the choice of population-assignment method substantially affects exposure and high sleep disturbance estimates. The largest absolute differences were observed where the relevant nighttime exposure coincided with larger retained residential populations, particularly in San Bartolo and Solanda. Relative sensitivity indicators showed a different ordering, highlighting the need to distinguish practical burden differences from proportional methodological sensitivity. These findings indicate that urban-form descriptors are useful for contextualising method sensitivity, although the results should be interpreted as descriptive rather than causal. At the aggregate level, the estimated HSD varied from 283.8 under M2 to 718.5 under M1, a 2.5-fold difference. The greatest burdens were focused on San Bartolo and Solanda. The proposed workflow presents a clear and replicable method for turning noise maps into actionable exposure and health indicators in data-limited urban contexts.