Sensory design with scent: Exploring the impact of ambient smell on emotions and physiological responses in the office environment

• The mixed-method approach provides a comprehensive understanding of ambient smells' effects on emotions. • Exposure to peppermint scent decreased theta band power and increased beta band power. • Exposure to rooms with different scents led to changes in autonomic indicators, including EDA and BVP. • Participants in the peppermint-scented room reported feeling less guilt and hostility. • Participants in the peppermint-scented room reported feeling less sluggish and dull. People spend a significant amount of time in indoor spaces. Consequently, the characteristics of the built environment can have a wide range of impacts on human emotions, mood, behavior, and well-being. Despite this, olfactory parameters have received less attention in studies of Indoor Environmental Quality (IEQ) compared to other aspects. This paper presents part of a series of experiments designed to study the impacts of indoor smells on humans using a mixed-method approach. In this single-blind experiment, 30 participants (15 females and 15 males) were placed in two identical controlled test rooms. In one room, the scent of peppermint was released, while the other room served as a control, maintaining only the inherent scents from materials, furniture, and human activities (odorless room). The findings indicate that exposing participants to identical rooms with differing ambient smells leads to changes in autonomic and central nervous system indices, as well as emotional responses. The Electroencephalography (EEG) analysis revealed that exposure to peppermint scent resulted in a reduction in theta band power and an increase in beta band power. The analysis revealed that some parameters of peripheral signals, including Electrodermal Activity (EDA) recorded from participants, differed between the peppermint-scented room and the odorless room. Analysis of self-report data revealed that participants exposed to the peppermint scent experienced more pleasant emotions, with lower levels of guilt, hostility, sluggishness, and dullness, compared to when they were in the odorless room.