Enhancing Adaptive Acoustic Comfort in Open-Plan Offices Through Green Window Views and Auditory Biophilic Elements

Naturally ventilated office spaces present a dual challenge: open windows are sources of thermal comfort and acoustic disturbances. Despite growing interest in adaptive comfort frameworks, the acoustic adaptation effects specific to naturally ventilated indoor environments and the role of biophilic design elements in mediating them remain insufficiently investigated. This study was conducted to examine the influence of audio–biophilic elements in a naturally ventilated space with a green view, with 53 participants recruited from a real, operational open-office space. Under typical open window field noise conditions, four levels of birdsong (45, 49, 52, and 55 dBA) were introduced at the receiver position. The participants’ perceptual responses were measured using the ISO/TS 12913:2019 and ISO/TS 12913:2025, as well as indoor-soundscape scales. Satisfaction, the perceived appropriateness of the conditions for work, and preferences were evaluated. Environmental descriptors, including psychoacoustic and thermal parameters and perceived auditory and visual content, were also recorded. Statistical analyses were conducted using RM-ANOVA, the Friedman test, and post hoc comparisons. The results revealed that audio–biophilic interventions can enhance adaptive acoustic comfort in naturally ventilated spaces. Although the existing ISO and indoor soundscape scales are highly correlated, they are not interchangeable. These findings offer actionable guidance for acoustic designers and facility managers: introducing contextually appropriate birdsong at moderate levels (not exceeding a background noise level of more than 3 dBA) can serve as an effective masking strategy in naturally ventilated open-plan offices without increasing perceived disturbance, supporting the integration of audio–biophilic systems in green building design. This study contributes field-based evidence to the literature on audio–biophilic interventions and their role in adaptive acoustic comfort in naturally ventilated spaces.