2.4.2 Modification of the olfactory identification test
(1) Preparation of the olfactory test: First, we did not change the odors in the SSOI test but adjusted the distractors according to the odor familiarity results and randomly replaced the unfamiliar distractors with the distractors with a odor familiarity score hi-gher than 7522, to form the MDOI test. Then, we used tetrahydrothiophene, 2-methylpy-razine, and trimethylindole to simulate natural gas, burnt smell, and fecal odor, respecti-vely, and distractors were randomly assigned to the three odors.
(2) Olfactory identification test modification: First, the SSOI test was conducted on 100 volunteers. Then the volunteers were tested by MDOI test after 30 minutes, with the test process unchanged. Finally, the volunteers were tested with three odors of natural gas, burnt smell, and Fecal odor to complete the olfactory identification test.