Investigating the effect of different smells in the indoor built environment (office) on human emotions using a mixed-method approach

Despite numerous studies highlighting the impact of smells on humans, there has been a notable lack of attention to ambient smell within the discipline of architecture. To address the gaps, a systematic methodology was designed to investigate the impact of the indoor-built environment's smell on human emotions. In this experiment, 14 adults (7 women and 7 men) are exposed to the smell of jasmine and rotten orange peel in two identical rooms. The EEG analysis revealed increased theta band power in frontal regions and increased alpha power in frontal and occipital areas when participants were exposed to the jasmine scent. Gamma activity in the frontal regions increases with exposure to the smell of rotten orange peel. Participants reported that the smell of jasmine was pleasant, leading to pleasant emotions, interest, enjoyment and a sleepy state. However, the smell of rotten orange peel led to unpleasant emotions, discomfort and annoyance for participants.