The Olfactory Fade

If you could choose for your room to smell like the inside of a Starbucks or a Raising Cane’s, which one would you pick? The warm aroma of espresso beans or the deep scent of fried chicken are both equally inviting. Personally, though, I’m more sensitive to strong, lingering smells, so I wouldn’t choose either. After a while, those scents start to give me a headache, and it takes time before the air feels clear again.

This made me wonder. Why are some people more sensitive to smells than others? And how long does it take before those smells fade into the background?

When you're exposed to a scent for a long time, your brain gradually stops responding to it. There's no urgent threat or reason to stay alert, so the brain shifts focus. This process is called olfactory adaptation, a specific kind of sensory adaptation. The receptors in your nose slow down their signals, and eventually, your brain decides the smell isn’t important enough to keep noticing.

Olfactory adaptation is one of the easiest forms of sensory adaptation to notice. The initial strong scent is always the strongest: think about the first whiff of Cane’s sauce or a fresh latte when you first walk in. After just a few minutes, it seems to fade, even though it's still there. For many people, this happens quickly. But not everyone’s brain adjusts in the same way. Some people with migraines, sensory processing sensitivity, or neurodivergent traits may take longer to adapt, or they might not adapt much at all. For them, the scent stays just as intense or becomes even more irritating.

Our brains are designed to filter out what isn’t essential, helping us conserve brain energy. But what one brain sees as background noise, another might experience as a constant distraction. Being sensitive to smell is not always a bad thing, and it can be interesting to see the sensory adaptation levels of those around you. 

References

Pamela Dalton, Psychophysical and Behavioral Characteristics of Olfactory Adaptation, Chemical Senses, Volume 25, Issue 4, August 2000, Pages 487–492, https://doi.org/10.1093/chemse/25.4.487