What is sound? If we look for its definition in physics books, we will see that it is a mechanical wave. When we speak, there is a displacement of air particles, which propagate in the form of waves that can be decoded by our ears. However, we know very well the difference between hearing any noise and a melody that we like.
Joy, nostalgia, and memories— is it not fascinating the power that music has to make us transition between different emotional states? In fact, studies show that when we listen to music, brain areas responsible for emotions, as well as the mesolimbic-dopaminergic circuit (involved in natural rewards, such as food and sex), are activated, which is reflected in our feelings (Koelsch, 2010).
A study published in The Journal of Pain in 2011 showed that music helps relieve pain. The study evaluated about 150 individuals, who were asked to identify certain variations in pitch in a piece of music while receiving painful stimuli. The stimuli consisted of a safe but uncomfortable electric shock to the fingertips at three different intensities: low, moderate, and high. The results showed that the discomfort caused by the painful stimulus decreased when participants focused on the task of identifying the tones, indicating that engagement with music can provide relief from pain. The study also showed that more anxious individuals and those with greater concentration capacity had the best responses (less pain), suggesting that individual characteristics play a role in modulating this effect.
In addition to music, other sounds can interfere with our senses, as concluded by a study published in Chemical Senses (2010) that showed this effect on smell. In the first experiment, participants were exposed to the sounds of "eating fries" or "drinking coffee" and the smells of fries or coffee. The audio and aroma were presented in a congruent (corresponding sound and smell) or incongruent (non-corresponding sound and smell) manner. At the end, the odors were rated as more pleasant when paired with the corresponding sound. In the second experiment, participants listened to pleasant sounds (a baby laughing or jazz music) or unpleasant sounds (a baby crying or screams) before and during the presentation of a pleasant or unpleasant odor. The results showed a correlation between the hedonic value of the sound and the evaluation of the subsequent smell, that is, the more participants appreciated the sound they heard, the more the subsequent odor was rated as pleasant. Together, the two experiments demonstrated that hearing can interfere with smell.
The ability of music to influence our response to pain and the ability of sounds to alter how we evaluate smells is only possible thanks to the existing interaction between the senses. Much of what we perceive through a certain sensory modality can be influenced by another sense; therefore, could we not provide more pleasant experiences during the use of products if we know how to stimulate different senses simultaneously?
References
Bradshaw DH, Donaldson GW, Jacobson RC, Nakamura Y, Chapman CR. Individual differences in the effects of music engagement on responses to painful stimulation. J Pain. 2011;12(12):1262-73;
Koelsch S. Towards a neural basis of music-evoked emotions. Trends in Cognitive Sciences. 2010;14(3):131-137;
Seo HS, Hummel T. Auditory-olfactory integration: congruent or pleasant sounds amplify odor pleasantness. Chem Senses. 2011;36(3):301-9;
Figure: http://commons.wikimedia.org/wiki/File:Joueur_de_saxophone.jpg?uselang=pt-br
