DISCUSSION

In part I of our experiments, we wanted to test what smells our subjects can identify, without teaching them. We found that our subjects correctly identified “everyday smells” correctly 61% of the time. We used common spices and fruits from the kitchen for this part of the testing. To study the potential interference of loud noise on the ability to recognize “everyday smells”, we then choose new smells and turned on the loud music. We were surprised to find that smell recognition went down to 50%. This illustrates that the loud noise which is transmitted to our hearing apparatus in our ear and then auditory nerve, and finally hearing cortex in the brain, somehow interferes with our sense of smell, which is the pathway from our nose to the olfactory bulb in the fore brain, and then the smell cortex. 

In part II of our experiments, we taught our subjects which smells we would be testing, therefore, before the introduction of the loud noise they scored 100%. To our surprise, when we did the interference experiments, the smell recognition went down from 100% to 61%. When we were doing the experiments, the subjects commented on how difficult it was to remember the smells, when the loud noise went into their ears. Again females did better than males in this part as well.

The purpose of our science fair projects this year and last was to demonstrate the concept that all the five senses are related. We hypothesize that all five human senses (seeing, hearing, smelling, tasting, and feeling) are related and this year we tested the influence of hearing on the sense of smell. The problem we wanted to study was that the human brain can only handle a certain amount of sensory information. We hypothesized that overloading our sense of hearing (by increasing the amount of noise) would result in a decrease in the sensitivity of smell. We provide good evidence that our hypothesis was true, and we show that we accepted our hypothesis.

We hope that our results about the interrelationships between human senses will stimulate neuro-scientists to investigate our findings by studying the changes by functional magnetic resonance imaging (fMRI) and positron emission tomography (PET scanning), during our experimental conditions. The future of this field is in newer ways to look at the brain. Next year we will test hypotheses about the relationship(s) between taste and hearing and try to expand on this and last years projects.