Chemosensory Perception

, Volume 11, Issue 1, pp 35–41 | Cite as

Fast Olfactory Threshold Determination Using an Ascending Limits Procedure

  • Rik Sijben
  • Claudia Panzram
  • Rea Rodriguez-Raecke
  • Thomas Haarmeier
  • Jessica Freiherr



The Sniffin’ Sticks test battery is currently considered the best alternative for the measurement of olfactory threshold, discrimination and identification capabilities. These tests still suffer from limitations, however. Most noticeably, the olfactory threshold test is an intensive task which requires participants to smell a large number of olfactory stimuli. This proves especially problematic when measuring olfactory performance of elderly patients or screening research subjects, as sensory adaptation plays an important role in olfactory perception.


In the current study, we have determined that the cause of this limitation lies with the test’s single-staircase procedure (SSP). Consequentially, we have devised an alternative ascending limits procedure (ALP). We here compared data obtained using both procedures, following a within-subject design with 40 participants. Olfactory threshold scores as well as number of trials required to complete the two procedures were investigated.


The results show that the ALP provides reliable and correct olfactory threshold ratings, as the values showed a good correlation with those obtained using the SSP and mean values did not differ significantly. Task duration, however, did show a highly significant difference, completing the SSP required participants to complete over 40% more trials compared to the ALP.


The here presented methodological improvement can save time and, more importantly, reduce participants’ cognitive and sensory strain, which is not only more comfortable, but also limits the influence of adaptation, making any measured data more reliable.


Improving standard screening methods can directly enhance the reliability of any future study using this procedure.


Sniffin’ Sticks TDI Psychophysics n-butanol Threshold 


Compliance with Ethical Standards


The project was funded by a grant from the Interdisciplinary Centre for Clinical Research within the Faculty of Medicine at the RWTH Aachen University (IZKF Project N7-9).

Conflict of Interest

The authors declare that they have no conflicts of interest.

Ethical Approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

The study was approved by the ethics board of the Medical Faculty of the University Hospital, RWTH Aachen University.

Informed Consent

Informed consent was obtained from all individual participants included in the study.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2017

Authors and Affiliations

  1. 1.Diagnostic and Interventional Neuroradiology, University HospitalRWTH Aachen UniversityAachenGermany
  2. 2.Fraunhofer Institute for Process Engineering and Packaging IVV, Department of Sensory AnalyticsFreisingGermany
  3. 3.Neurology DepartmentHELIOS Klinikum KrefeldKrefeldGermany
  4. 4.Neurology Department, University HospitalRWTH Aachen UniversityAachenGermany

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