Arnal and teammates probed what sorts of sounds alarm humans. They found that “One strategy, exploited by alarm signals, consists in emitting fast but perceptible amplitude modulations in the roughness range (30–150 Hz). . . . Rough sounds synchronise activity throughout superior temporal regions, subcortical and cortical limbic areas, and the frontal cortex, a network classically involved in aversion processing.” Rough sounds from 40-80 Hz are especially unpleasant for us to hear. The 40-80 Hz range is where the frequencies of babies crying, human screams, and many alarms are found.
Relaxation, stress, and anxiety affected
Researchers from the Universidad Carlos III de Madrid, the University of Sussex, and University College London investigated how scents and sounds influence our perceptions of our bodies. The team found “that olfactory stimuli combined with auditory stimuli can change our perception of our body. . . . People feel thinner and lighter when exposed to the smell of lemon, while feeling heavier and more corpulent when they smell vanilla. . . . Through a device adapted to a pair of shoes . . . .
Hearing low frequencies has significant effects on life experiences. Scientists report “this exploratory study was designed to investigate the effects of lower frequency sound (10 Hz to 200 Hz) on the perception of the mouthfeel character of palate weight/body. . . . Wines were the tastants — a New Zealand Pinot Noir and a Spanish Garnacha — which were tasted in silence and with a 100 Hz (bass) and a higher 1000 Hz sine wave tone. . . .
How does music heard while dining influence the eating experience? Reinoso-Carvalho and colleagues report that “two contrasting music tracks (positive vs negative emotion) were presented to consumers while tasting beer. . . . Participants liked the beer more, and rated it as tasting sweeter, when listening to music associated with positive emotion. The same beer was rated as more bitter, with higher alcohol content, and as having more body, when the participants listened to music associated with negative emotion.
Lin and teammates investigated multi-sensory experiences involving sound. In a lab, they probed “the effects of environmental sounds (park, food court, fast food restaurant, cafe, and bar sounds) on the perception of chocolate gelato (specifically, sweet, bitter, milky, creamy, cocoa, roasted, and vanilla notes). . . . The results revealed that bitterness, roasted, and cocoa notes were more evident when the bar, fast food, and food court sounds were played. Meanwhile, sweetness was cited more in the early mastication [chewing] period when listening to park and café sounds.”
Bild and colleagues studied responses to soundscapes in public spaces. They determined via data collected in Amsterdam that “solitary and socially interactive respondents [people in the public spaces investigated] evaluate their soundscapes differently. . . . The sounds of people were considered as the main source of both disruption and stimulation for both groups; while conversations and the sounds of others in general were referred to as stimulating, loud conversations and children crying were disrupting.
Zalejska-Jonsson investigated people’s acoustic experiences in their homes. She found that “experiencing noise from neighbours occurred relatively seldom; however, this factor has the strongest effect on satisfaction with acoustic quality.” Data were collected in multistory residential buildings.
Agnieszka Zalejska-Jonsson. 2019. “Perceived Acoustic Quality and Effect on Occupants’ Satisfaction in Green and Conventional Residential Buildings.” Buildings, vol. 9, no. 1, https://doi.org/10.3390/buildings9010024
Adhering to guidelines no guarantee of higher satisfaction
Managing background noise also vital