HNO
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Specific anosmia, the inability to perceive a specific odor, while olfactory perception is otherwise intact, is known as a rather seldom phenomenon. By testing the prevalence of specific anosmia to 20 different odors in a sample of 1600 people, we were able to estimate the general prevalence of anosmia. This revealed that specific anosmia is not rare at all. ⋯ In addition, specific anosmia can be very well reversed by "smell training" during the course of 3 months. To summarize, specific anosmia seems to be a rule, not an exception, of olfactory sensation. The lack of perception of certain odors may constitute a flexible peripheral filter mechanism, which can be adapted by exposure to odors.