Pentatonic sequences and monaural beats to facilitate relaxation: an EEG study

Introduction

In two studies we investigated if specific acoustic stimulations could be more effective to induce a relaxation response in comparison to silence. Acoustic stimulations included monaural beats and musical sequences based on a pentatonic scale.

Methods

In the first study, 47 participants evaluated monaural beats and pentatonic sequences presented through loudspeakers and varying along three frequencies (0.2, 2, 4 Hz). In the second study, 31 participants relaxed with their eyes closed for 10 min during a passive listening of monaural beats and a pentatonic sequence presented through loudspeakers. A silence condition was introduced as control. All auditory stimuli were designed with a temporal modulation of 0.2 Hz. Concomitant EEG was recorded with a 64-channel system and spectral analysis was performed on delta, theta, alpha, beta, and gamma oscillations to test if each of the three auditory stimulations had a significant effect on EEG spectral power in comparison to silence.

Results

In the first study, pentatonic sequences were evaluated as more pleasant and more relaxing than monaural beats. Pleasantness and relaxation were inversely related to frequency. Visual imagery and emotion induction had higher frequency and were rated with a more positive valence in pentatonic sequences than in monaural beats. In the second study monaural beats in comparison to silence strongly decreased beta and gamma oscillations in the first three minutes and strongly increased theta oscillations in the last three minutes. Pentatonic sequences increased delta, theta, and alpha oscillations in the last three minutes while decreasing beta, and gamma oscillations for the whole auditory stimulation.

Discussion

The results show that auditory signals with a very low temporal modulation (0.2 Hz) could be more effective than silence in inducing a relaxation response. Although 0.2 Hz monaural beats were effective in inducing a relaxation response, they tended to be perceived as unpleasant. Pentatonic sequences could be considered as a better alternative to promote relaxation by auditory stimulation.

Noise sensitivity or hyperacusis? Comparing the Weinstein and Khalfa questionnaires in a community and a clinical samples

Noise sensitivity and hyperacusis are decreased sound tolerance conditions that are not well delineated or defined. This paper presents the correlations and distributions of the Noise Sensitivity Scale (NSS) and the Hyperacusis Questionnaire (HQ) scores in two distinct large samples. In Study 1, a community-based sample of young healthy adults (n = 103) exhibited a strong correlation (r = 0.74) between the two questionnaires. The mean NSS and HQ scores were 54.4 ± 16.9 and 12.5 ± 7.5, respectively. NSS scores displayed a normal distribution, whereas HQ scores showed a slight positive skew. In Study 2, a clinical sample of Veterans with or without clinical comorbidities (n = 95) showed a moderate correlation (r = 0.58) between the two questionnaires. The mean scores were 66.6 ± 15.6 and 15.3 ± 7.3 on the NSS and HQ, respectively. Both questionnaires' scores followed a normal distribution. In both samples, participants who self-identified as having decreased sound tolerance scored higher on both questionnaires. These findings provide reference data from two diverse sample groups. The moderate to strong correlations observed in both studies suggest a significant overlap between noise sensitivity and hyperacusis. The results underscore that NSS and HQ should not be used interchangeably, as they aim to measure distinct constructs, however to what extent they actually do remains to be determined. Further investigation should distinguish between these conditions through a comprehensive psychometric analysis of the questionnaires and a thorough exploration of psychoacoustic, neurological, and physiological differences that set them apart.

Indoor soundscape in primary school classroomsa)

Soundscape research on indoor environments is emerging as a topic to be addressed for the design of supportive, healthier, and more comfortable spaces. Only a few studies so far addressed the context of educational buildings, mainly focusing on high schools and universities. This pilot study uses questionnaires based on pictorial scales to investigate the indoor soundscape of classrooms for primary school children (n = 130; 8-10 years old). Perceived loudness and the affective dimensions of pleasantness and arousal were explored. Besides the actual soundscape, the children's ideal soundscape was investigated as well. The results of the study indicate that the most frequent sounds in classrooms are generated by the students themselves (voices, movements) followed by the traffic. The urban context of the school modulates the children's perception when windows are open to ensure natural ventilation. Pleasantness is associated with students' age, perceived loudness, and frequency of children's voices in nearby classrooms. The frequency of hearing indoor sounds (children's voices) and sirens affects students' arousal. Our results indicate that children at school are mostly exposed to unpleasant sounds, whereas their preferred ones are music and nature-related ones. The findings have implications for the design of positive and inclusive learning environments.

Be Quiet! Effects of Competing Speakers and Individual Characteristics on Listening Comprehension for Primary School Students

Students learn in noisy classrooms, where the main sources of noise are their own voices. In this sound environment, students are not equally at risk from background noise interference during lessons, due to the moderation effect of the individual characteristics on the listening conditions. This study investigates the effect of the number of competing speakers on listening comprehension and whether this is modulated by selective attention skills, working memory, and noise sensitivity. Seventy-one primary school students aged 10 to 13 years completed a sentence comprehension task in three listening conditions: quiet, two competing speakers, and four competing speakers. Outcome measures were accuracy, listening effort (response times and self-reported), motivation, and confidence in completing the task. Individual characteristics were assessed in quiet. Results showed that the number of competing speakers has no direct effects on the task, whilst the individual characteristics were found to moderate the effect of the listening conditions. Selective attention moderated the effects on accuracy and response times, working memory on motivation, and noise sensitivity on both perceived effort and confidence. Students with low cognitive abilities and high noise sensitivity were found to be particularly at risk in the condition with two competing speakers.

Effects of spatialized water-sound sequences for traffic noise masking on brain activities

Informational masking of water sounds has been proven effective in mitigating traffic noise perception with different sound levels and signal-to-noise ratios, but less is known about the effects of the spatial distribution of water sounds on the perception of the surrounding environment and corresponding psychophysical responses. Three different spatial settings of water-sound sequences with a traffic noise condition were used to investigate the role of spatialization of water-sound sequences on traffic noise perception. The neural responses of 20 participants were recorded by a portable electroencephalogram (EEG) device during the spatial sound playback time. The mental effects and attention process related to informational masking were assessed by the analysis of the EEG spectral power distribution and sensor-level functional connectivity along with subjective assessments. The results showed higher relative power of the alpha band and greater alpha-beta ratio among water-sound sequence conditions compared to traffic noise conditions, which confirmed the increased relaxation on the mental state induced by the introduction of water sounds. Moreover, different spatial settings of water-sound sequences evoked different cognitive network responses. The setting of two-position switching water brought more attentional network activations than other water sequences related to the information masking process along with more positive subjective feelings.

The Restorativeness of Outdoor Historical Sites in Urban Areas: Physical and Perceptual Correlations

Growing tourist flows, which crowd ancient city centres, have modified their liveability and threatened conservation. They have increased the need for quiet places, primarily where green parks are missing. While previous studies have highlighted the possibility of reusing hidden sites of historical buildings, it is not clear if this scheme can also be applied in other contexts, and which physical or perceptual dimensions are mainly related to the restoration of these sites. If greenery and water elements induce positive effects on people’s well-being, we want to understand if the historical–artistic component can be just as important for people’s restorativeness. To this end, the physical and perceptual characteristics of 20 different sites in Naples and Istanbul were investigated through objective and subjective surveys. The results show that the sound levels inside sites cannot consistently account for the perception of the restorativeness in Italy and Turkey, while some sound level differences caused by outside noise could. Moreover, soundscape, appreciation, maintenance/management, and importance/relevance were the main perceptual dimensions describing these places. The importance/relevance dimension was strongly correlated with all the components of the restorativeness, especially with the fascination. These findings are consistent between the Italian and Turkish groups.

A Short Form of the Chinese Version of the Weinstein Noise Sensitivity Scale through Optimal Test Assembly

This study developed a short form of the traditional Chinese version of the Weinstein Noise Sensitivity Scale (WNSS) through optimal test assembly (OTA). A total of 1069 Chinese adults (64.8% female) completed the territory-wide cross-sectional study. We first removed Items 12 and 5 which had negative factor loading and gender-related differential item functioning (DIF), respectively. The optimal length was then determined as the minimal one that reasonably resembled the reliability and validity of the scale without DIF items. OTA identified an 8-item WNSS (WNSS-8) which retained 67.2% of the test information of the original 21-item scale and had a Cronbach's alpha of 0.83. It also showed significant correlations of 0.272 and -0.115 with the neuroticism and extraversion scales of Chinese NEO-Five Factor Inventory, respectively. Adequate model fit of the WNSS-8 was demonstrated by the confirmatory factor analysis. The Chinese WNSS-8 can be used to assess noise sensitivity without compromising reliability and validity.

The Factorial Structure of a 15-Item Version of the Italian Empathy Quotient Scale

Abstract. The Empathy Quotient (EQ) scale is a self-report measure designed to assess empathy in adults. Although the scale is widely used and has been validated into different languages, its dimensionality is still controversial, as well as it is not clear which scale version should be considered. The aim of the present study was to investigate the psychometric properties of the EQ scale. The Italian version of the EQ scale was administered to a sample of 633 adults. Results showed that the 15-item EQ scale version proposed by Muncer and Ling (2006) had excellent reliability and validity indices, with a gender invariant three-factor structure (Cognitive Empathy, Emotional Reactivity, and Social Skills) and a higher order factor of general empathy. The overall results confirmed that the 15-item EQ scale is an eligible and stable tool for the assessment of empathy.

Motivated Shield From Chronic Noise Environment: Moderation of the Relationship Between Noise Sensitivity and Work Wellbeing by Need for Closure

Several studies have underlined how chronic exposure to environmental noise may have negative effects on performance, wellbeing, and social relations. The present study (N = 90 employees of a motor factory who are chronically exposed to environmental noise) investigated whether the negative effects of chronic exposure of noise-sensitive individuals to noise in the workplace may be moderated by the need for cognitive closure (i.e., an epistemic tendency to reduce uncertainty; NFCC, Kruglanski, 2004). As NFCC has been shown to enhance protection of the focal goal by reducing interference (Kossowska, 2007; Pica et al., 2013), we hypothesized that people with high NFCC should be able to manage the interference coming from environmental noise and concentrate on their tasks more than their low-NFCC counterparts. The results confirm that the negative effects of noise sensitivity on job satisfaction, state anxiety, and turnover intent were higher among low (vs. high)-NFCC individuals.

Physiological and self-report responses of parents of children with autism spectrum disorder to children crying

Little is known about the physiological response of parents of children with Autism Spectrum Disorder (ASD) to crying of children who have already received the diagnosis of ASD. This study aimed to compare cardiac dynamics via Inter-Beat Interval (IBI) and self-reported emotional states of parents of children with ASD and of parents with typically developing (TD) children while listening to crying of children with ASD (ASD cry) and of typically developing children (TD cry). Analyses revealed higher IBI in parents of children with ASD than IBI in parents of TD children while listening to both cry groups; however no differences on self-reported emotional states were observed. Parents of children with ASD were calmer (higher IBI) than parents of TD children while listening to crying. However, ASD cry did not elicit different IBI compared to TD cry. ASD cry and TD cry were differentiated based on parents' self-responses about what they felt during the listening of crying, their physiological responses showed no differences. These results highlight the similarities and differences between self-reported emotional states and physiological responses of parents of children with ASD, and also point to the importance of monitoring parents' physiological responses in addition to their subjective responses.

Adults' implicit associations to infant positive and negative acoustic cues: Moderation by empathy and gender

In this study a novel auditory version of the Single Category Implicit Association Test (SC-IAT-A) was developed to investigate (a) the valence of adults' associations to infant cries and laughs, (b) moderation of implicit associations by gender and empathy, and (c) the robustness of implicit associations controlling for auditory sensitivity. Eighty adults (50% females) were administered two SC-IAT-As, the Empathy Quotient, and the Weinstein Noise Sensitivity Scale. Adults showed positive implicit associations to infant laugh and negative ones to infant cry; only the implicit associations with the infant laugh were negatively related to empathy scores, and no gender differences were observed. Finally, implicit associations to infant cry were affected by noise sensitivity. The SC-IAT-A is useful to evaluate the valence of implicit reactions to infant auditory cues and could provide fresh insights into understanding processes that regulate the quality of adult-infant relationships.

Noise sensitivity: A neurophenomenological perspective

This paper addresses the current limitations of noise sensitivity research and the benefit of undertaking a neurophenomenological approach of investigation. It begins by questioning the invariance of noise sensitivity across different studies and contexts and argues that these are issues associated with the psychometric construct rather than the underlying reaction patterns. It suggest that our definition and operationalization of noise sensitivity might have been misspecified and that it needs to be revised on the basis of heuristically derived first-person data about our experiences of noise. It then shows why the basic principles of the neurophenomenological program are applicable to psychoacoustic research. Namely, it argues that phenomenological training leading to reflexive introspection and verbalization of our susceptibility to noise might have three-fold implication - (i) it will generate deeper understanding of noise sensitivity which will then allow us to deduce a hierarchical structure of meaning and concepts to supplement and be fed to quantitative research, (ii) it will provide better interpretation of neuroimaging and electroencephalographic data related to noise reaction and perception, which in turn will allow a process of reciprocal validation, (iii) and, most importantly, it presents a promising technique for emotional regulation of noise processing via modulation of the amygdalar function, when a state of awareness of this processing has been achieved.

Auditory recognition of familiar and unfamiliar subjects with wind turbine noise

Considering the wide growth of the wind turbine market over the last decade as well as their increasing power size, more and more potential conflicts have arisen in society due to the noise radiated by these plants. Our goal was to determine whether the annoyance caused by wind farms is related to aspects other than noise. To accomplish this, an auditory experiment on the recognition of wind turbine noise was conducted to people with long experience of wind turbine noise exposure and to people with no previous experience to this type of noise source. Our findings demonstrated that the trend of the auditory recognition is the same for the two examined groups, as far as the increase of the distance and the decrease of the values of sound equivalent levels and loudness are concerned. Significant differences between the two groups were observed as the distance increases. People with wind turbine noise experience showed a higher tendency to report false alarms than people without experience.

The effects of vision-related aspects on noise perception of wind turbines in quiet areas

Preserving the soundscape and geographic extension of quiet areas is a great challenge against the wide-spreading of environmental noise. The E.U. Environmental Noise Directive underlines the need to preserve quiet areas as a new aim for the management of noise in European countries. At the same time, due to their low population density, rural areas characterized by suitable wind are considered appropriate locations for installing wind farms. However, despite the fact that wind farms are represented as environmentally friendly projects, these plants are often viewed as visual and audible intruders, that spoil the landscape and generate noise. Even though the correlations are still unclear, it is obvious that visual impacts of wind farms could increase due to their size and coherence with respect to the rural/quiet environment. In this paper, by using the Immersive Virtual Reality technique, some visual and acoustical aspects of the impact of a wind farm on a sample of subjects were assessed and analyzed. The subjects were immersed in a virtual scenario that represented a situation of a typical rural outdoor scenario that they experienced at different distances from the wind turbines. The influence of the number and the colour of wind turbines on global, visual and auditory judgment were investigated. The main results showed that, regarding the number of wind turbines, the visual component has a weak effect on individual reactions, while the colour influences both visual and auditory individual reactions, although in a different way.