The ISO 12913 series represents a paradigm shift in environmental acoustics by introducing a human-centered and perceptual framework for soundscape assessment. Although conceived as globally applicable, questions remain regarding its implementation in Global South contexts. This study evaluates how ISO 12913 is perceived, interpreted, and applied in Brazil, with the aim of identifying its strengths, limitations, and contextual adaptation needs in relation to soundscape standardization and sustainability. A mixed-methods approach was employed, combining an online survey with Brazilian soundscape researchers and practitioners and a virtual focus group with domain experts. Quantitative data were analyzed descriptively, while qualitative responses were examined through thematic analysis structured under a Societal Research Impact Assessment framework. The results indicate broad recognition of the conceptual relevance of ISO 12913, especially its interdisciplinary and human-centered approach. However, several challenges were identified, including linguistic and semantic inconsistencies in perceptual attributes, limited guidance for indoor soundscape assessment, conceptual ambiguities, and socioeconomic constraints affecting implementation. Participants highlighted the need for cultural, linguistic, and methodological adaptations to enable meaningful application within heterogeneous and resource-constrained contexts. By foregrounding the Brazilian experience, the study contributes to global debates on soundscape standardization, by demonstrating how international frameworks such as ISO 12913 can be refined through meaningful engagement with Global South contexts. The study supports the development of complementary national guidelines aimed at enhancing contextual adequacy, operational feasibility, and long-term societal impact, thereby fostering more inclusive and socially sustainable soundscape assessment practices.