Busier, more distracted people can be blind to smell.

According to a study from the University of Sussex, ‘inattentional smell blindness’, or inattentional anosmia, has been proven to exist.

Just as it has been proven that people tend to miss visual cues when engrossed in a task, the same applies to noticing new smells.

In the case of visual stimuli, once the person stops being busy the object or view in question will be noticed.

With smell, there is only a short window before the person becomes habituated to it, and the opportunity to notice it has passed.

“We have discovered that people are less likely to notice a smell if they are busily engaged in a task,” said Sophie Forster, one of the researchers on the study.

“Many of us have experienced this: we’ve been working in a room when a new person has entered and said that the room smells of something such as someone’s lunch, but that those already in the room had failed to notice it.

“What’s more, we found that because habituation to smells is much stronger than other senses, if we habituate during a period of distraction we might never notice a smell.

“Previous research has told us that, unique to the sense of smell, there is only a window of approximately 20 minutes before the brain is no longer able to detect it — a phenomenon known as olfactory habituation.”