The causes of such conditions are diverse, including head traumas, upper respiratory tract infections, neurodegenerative disorders, and OD secondary to sinonasal diseases. Olfactory disorders (OD) can be classified into two major groups: Reduced perception of odor intensity (quantitative impairment) and distorted odor perception (qualitative impairment). The sense of smell enables us to interact with our environment and olfactory impairment results in a loss of critical information. SSparoT might emerge as a valuable tool to assess qualitative olfactory function in health and disease. Analysis showed agreement between test–retest sessions for all odor pairs. Eleven odor pairs were found to be suitable for estimation of HR and HD. Cluster analysis was used to group odors from the 16-item Sniffin’ Sticks Identification test and 24-additional odors into clusters with distinct hedonic properties. This multicenter study enrolled a total of 162 normosmic subjects in four consecutive experiments. HR is defined as the perceivable hedonic distance between two oppositely valenced odors, while HD serves as an indicator for overall hedonic perception of odors. SSParoT uses hedonic estimates of two oppositely valenced odors (pleasant and unpleasant) to assess hedonic range (HR) and hedonic direction (HD), which represent qualitative olfactory perception. The newly developed test is called Sniffin’ Sticks Parosmia Test (SSParoT). We have developed a test method which measures qualitative olfactory function based on the odors of the Sniffin’ Sticks Identification subtest. Parosmia and phantosmia represent the two main subgroups of qualitative impairment and are currently diagnosed based on patient history only. Qualitative olfactory dysfunction is characterized as distorted odor perception and can have a profound effect on quality of life of affected individuals.

Hedonic scale