McFarlane and colleagues have investigated, via an online survey, the sorts of sounds that alarms to wake people up can make and the repercussions of awakening to various sounds. Their findings are generally relevant to people working on creating sounds that alert listeners. The McFarlane-lead team reports that “Sleep inertia is a potentially dangerous reduction in human alertness and occurs 0–4 hours after waking. . . . The goal of this research is to understand how a particular sound or music chosen to assist waking may counteract sleep inertia. . .
The cognitive science research is clear – using natural elements (for example, materials, sounds,
Perceptions and realities
Samermit and colleagues have determined that pairing disliked sounds (such as “nails scratching a chalkboard”) with videos presenting a more positive explanation for that sound (such as “someone playing a flute”) reduces the negative implications of hearing those sounds. They report that “We propose that cross-sensory stimuli presenting a positive attributable source of an aversive sound can modulate negative reactions to the sound.” The researchers utilized “original video sources (OVS) of eight aversive sounds (e.g., nails scratching a chalkboard) . . .
Astolfi and colleagues investigated the effects of classroom acoustics on the educational experiences of young people, age 6 to 7. They determined that “findings of the study suggest that long reverberation times, which are associated to poor classroom acoustics as they generate higher noise levels and degraded speech intelligibility, bring pupils to a reduced perception of having fun and being happy with themselves.
Christensen, Lindén, Nakamura, and Barkat determined that white noise can improve ability to hear other sounds and their work is published in Cell Reports. The investigators found via studies with mice that “With a background of continuous white noise, hearing pure sounds becomes even more precise. . . .the more precisely we can distinguish sound patterns, the better our hearing is. But how does the brain manage to distinguish between relevant and less relevant information – especially in an environment with background noise? . . .
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. . . .