Grades K–2 · Organisms
Why can a smell become less noticeable after a while?
A room may have a smell that stands out when you first enter. After you have been there a while, you may notice it less. The smell does not have to disappear for this to happen.
In the diagramNoticeability can change while odor remainsAt firstLatersame symbolic odor supply; different responseIllustrative response bars; a smell’s strength does not establish safe air.
Your nose and brain do not respond to every repeated message in exactly the same way forever. Responses can change as a smell continues. What you pay attention to also affects how much it stands out.
A new or changed smell may catch your attention again. But how strong a smell feels does not tell you everything about the air. Becoming used to a smell and removing the substance are different changes.
About this explanation
Starting knowledge: Know that the nose senses substances in air and sends messages through the nervous system.
Sources
- Noam Sobel and colleagues, Journal of Neurophysiology — Time Course of Odorant-Induced Activation in the Human Primary Olfactory Cortex
- National Institute on Deafness and Other Communication Disorders — Smell Disorders: How does your sense of smell work?