2.1 Participants
We recruited 200 volunteers with normal olfaction from 2021 to 2022. The first 100 volunteers (42 males and 58 females, aged 18–65 years, mean age 35.70 years,SD 10.88) participated in the odor familiarity survey. The remaining 100 volunteers (61 males and 39 females, aged 18–60 years, mean age 34.38 years, SD 11.00) participated in the modi-fication of the olfactory identification test. They reported having no obvious olfactory di-sorder and no previous history of nasal craniocerebral surgery. Physical examination sho-wed that both nasal cavities and olfactory clefts were unobstructed. Signed informed con-sent was obtained.All procedures used in this experiment involving human participants were approved by the Ethics Committee and were in accordance with the Declaration of Helsinki.