Indoor soundscapes significantly impact wellbeing, yet methodologies for understanding their perception among older adults remain underdeveloped. This paper presents Soundscape Experience Mapping (SEM), combining ecological momentary assessment with participatory design methods to capture and analyse indoor acoustic environments. Through structured listening activities and audio data collection, participants document their acoustic experiences in context. Our pilot study engaged eight older adults (57+) in a town in Belgium, collecting continuous audio recordings and qualitative data over one week. Using momentary judgements , retrospective evaluations, and sound journalling, we gained insights into how older adults perceive their indoor soundscapes. The method produced findings on the personal control of sound environments, soundscape preferences, and how situational factors influence acoustic perception. Participants demonstrated agency in curating their sonic environments, while expressing frustration with uncontrollable sounds. Daily routines and domestic rhythms emerged as key contextual factors shaping sound-scape experiences. This work advances AI-assisted indoor soundscape design by providing evidence-based methods to understand occupant needs, particularly for older adults who could benefit from tailored acoustic environments.