Olfaction

thumb|upright=1.25|"Smell", from Allegory of the Senses by Jan Brueghel the Elder, [[Museo del Prado ]]

sense that detects odors

thumb|Musk deer of Tibet in an 1835 illustration

thumb|Soil and water being splashed by a raindrop

sensor

chemical compound that has a smell or odor

Hyposmia, or microsmia, is a reduced ability to smell and to detect odors. A related condition is anosmia, in which no odors can be detected. Some of the causes of olfaction problems are allergies, nasal polyps, viral infections and head trauma. In 2012 an estimated 9.8 million people aged 40 and older in the United States had hyposmia and an additional 3.4 million had anosmia/severe hyposmia.

Parosmia (from the Greek παρά pará and ὀσμή osmḗ "smell") is a dysfunctional smell detection characterized by the inability of the brain to correctly identify an odor's "natural" smell. Instead, the natural odor is usually transformed into an unpleasant aroma, typically a "burned", "rotting", "fecal", or "chemical" smell. There can also be rare instances of a pleasant odor called euosmia. The condition was rare and little-researched until it became relatively more widespread since 2020 as a side effect of COVID-19.

piece of bone in the breathing passage of humans and other animals

component of a fragrance

Hyperosmia is an increased olfactory acuity (heightened sense of smell), usually caused by a lower threshold for odor. This perceptual disorder arises when there is an abnormally increased signal at any point between the olfactory receptors and the olfactory cortex. The causes of hyperosmia may be genetic, hormonal, environmental or the result of benzodiazepine withdrawal syndrome.

orientation scent released by worker bees

lowest perceivable odor concentration

Smell-O-Vision is a system that released odor during the projection of a film so that the viewer could "smell" what was happening in the movie. Created by Hans Laube, the technique made its only appearance in the 1960 film Scent of Mystery, produced by Mike Todd Jr., son of film producer Mike Todd. The process injected 30 odors into a movie theater's seats when triggered by the film's soundtrack.

technique in which a dog is used to locate an object by scent

unit used to measure the strength of a pollution source

art form that uses scent as a medium

the study of smelling things through a computer

term

practice of using dogs senses of smell to detect cancer

thumb|An entomologist demonstrates the attraction of female yellow fever mosquitoes to his hand in an olfactometer An olfactometer is an instrument used to detect and measure odor dilution. Olfactometers are used in conjunction with human subjects in laboratory settings, most often in market research, to quantify and qualify human olfaction. Olfactometers are used to gauge the odor detection threshold of substances. To measure intensity, olfactometers introduce an odorous gas as a baseline against which other odors are compared.

recollection of odors