Evaluation of soundscape authenticity in historic districts: weighted formulae and spatial typology-based sound selection

As vital carriers of urban architectural heritage, historic districts are increasingly central to urban planning agendas concerning the preservation of their authenticity. However, current research predominantly emphasises visual perception and design strategies, often neglecting the unique role of sound in shaping authenticity. This research proposes a transferable sound selection methodology for enhancing authenticity, based on audiovisual simulation and perceptual evaluation. First, the study identifies two dimensions for evaluating sound-based authenticity: original memory and cultural characteristic. A weighted calculation formula is established to enable the quantification of authenticity, supporting evidence-based decision-making in urban conservation efforts. Second, the spatial types of historic districts are categorised into three clusters: Commercial space, cultural space and residential space . Five spatial feature indicators are identified as effective discriminants of these clusters. Third, a dominant sound selection method is proposed for each spatial type. Finally, this study recommends the optimal sound combinations that enhance authenticity in different spatial contexts. For instance, in commercial space , mechanical sounds dominate, with moderate inclusion of natural sounds and a reduction in human sounds. By introducing a quantitative indicator system, this research advances the qualitative limitations, supporting urban planners and policymakers in developing sound-based strategies for preserving the authenticity of historic districts.