Purpose To investigate the clinical utility of q-Powders—a retronasal identification screening test. Methods A total of 156 subjects (92 females, mean age: 54.5 years ± 17.3 years) completed a 3-item q-Powders retronasal identification test and a 16-items Sniffin’ Sticks orthonasal identification test. We analyzed whether the q-Powders test could differentiate between subjects with normosmia and subjects with an olfactory disorder. Results Our data indicated that subjects with an olfactory disorder scored lower in the q-Powders test than subjects with normosmia. The analyses revealed q-Powders test sensitivity of 84% and a test specificity of 64.9% with a score of 2 points taken as a cutoff for olfactory disorders. Conclusion The 3-item q-Powders retronasal test may be used for screening purposes in clinical research. Level of evidence 4

Introduction Evidence accumulates to support the interaction among gustatory, olfactory and trigeminal sensations. While olfactory dysfunction is associated with impaired taste or intranasal trigeminal perception, less is known about the perception of oral irritative intensity among patients with olfactory or gustatory dysfunctions. Method 148 patients with olfactory and/or gustatory dysfunctions received oral administration of chili powder samples with varied irritation levels, and rated the oral irritation intensity on an 11‐point scale. Gustatory sensitivity was assessed using the ‘Taste Strips’ test among a subset of the patients (N = 25). Other variables including the aetiology of disease and a frequency of spicy food consumption were also recorded for exploratory analyses. Results Participants with anosmia rated oral irritations of chili powder significantly less than participants with normosmia. In the subsample, a positive correlation was observed between the individual scores of the ‘Taste Strips’ test and ratings of oral irritation intensity at the highest level of chili powder test. There were no effects of age, aetiology, subjective ratings of sensitivity to spicy food or frequency of spicy food consumption with respect to oral irritation intensity of chili powder samples. Conclusion The current results showed reduced oral irritation intensity among patients with severe olfactory loss. Impaired oral irritative perception among these participants may be related to disturbed central nervous interactions between the various sensory systems involved in flavour perception.

Background A precise and reliable test of the olfactory function is indispensable for the diagnosis of the olfactory disorder (OD). Despite of this, in a clinical context, often there is no place in daily routine for time-consuming procedures. This study aimed to examine if the assessment of olfactory function using the “Sniffin’ Sticks” is suitable for self-assessment. Methods Participants comprised 84 healthy control subjects (HC) and 37 OD patients. The “Sniffin’ Sticks” test battery consisting of odor threshold (T), discrimination (D) and identification (I) tests was used for self- and assisted assessments. To save time, we applied the 8-item wide step version of the T test and the 8-item D test, whereas the I task remained the same as the original version. The whole test included two sessions, with each session comprising a self-assessment part performed by the participants themselves, and an assisted-assessment part performed by the examiner. Results Sniffin’ Sticks self-assessment was efficient in distinguishing between self-reported HC subjects and OD patients (p’s < 0.01), and the scores did not differ significantly from the assisted-assessment (p’s > 0.05). In the self-administered I and TDI tests, there was a moderate to excellent test–retest reliability (ICC = 0.51–0.93, p’s < 0.01), and a strong to excellent correlation with the assisted assessment (r = 0.71–0.92, p’s < 0.01). However, the self-administered T and D tests only exhibited low to moderate test–retest reliability (ICC = 0.30–0.72, p’s < 0.05) and correlations with the assisted test (r = 0.31–0.62, p’s < 0.05). Conclusions The Identification self-test is appropriate to be solely applied, and is therefore an easy-to-use alternative for olfactory screening in a larger segment of patients. The whole “Sniffin’ Sticks” self-test also shows good measurement properties and is therefore a suitable backup in clinical practice, but improvement is needed due to the simplified D and T self-test.

Olfaction, i. e., the sense of smell is referred to as the 'emotional sense', as it has been shown to elicit affective responses. Yet, its influence on speech production has not been investigated. In this paper, we introduce a novel speech-based smell recognition approach, drawing from the fields of speech emotion recognition and personalised machine learning. In particular, we collected a corpus of 40 female speakers reading 2 short stories while either no scent, unpleasant odour (fish), or pleasant odour (peach) is applied through a nose clip. Further, we present a machine learning pipeline for the extraction of data representations, model training, and personalisation of the trained models. In a leave-one-speaker-out cross-validation, our best models trained on state-of-the-art wav2vec features achieve a classification rate of 68 % when distinguishing between speech produced under the influence of negative scent and no applied scent. In addition, we highlight the importance of personalisation approaches, showing that a speaker-based feature normalisation substantially improves performance across the evaluated experiments. In summary, the presented results indicate that odours have a weak, but measurable effect on the acoustics of speech.