Daniela Gentile

Negli ultimi due decenni, i Sound Studies e le Sonic Arts hanno esplorato il rapporto tra suono e potere, studiando il suono come fenomeno vibrazionale e relazionale, contribuendo allo sviluppo di pratiche che spostano l’attenzione da un approccio cocleare a uno non-cocleare, sulla base delle ricerche in ambito medico-scientifico che hanno evidenziato i benefici del suono sulla salute psicofisica. Tuttavia, il suono viene anche utilizzato come strumento di controllo e coercizione. In contesti militari e quotidiani, infrasuoni e ultrasuoni vengono sfruttati per provocare paura, oppressione e manipolazione emotiva e fisiologica. Il testo discute e sostiene l'ascolto come un atto di resistenza eco-politica: l’ascolto, come atto consapevole, si costituisce come strumento per sovvertire le strutture oppressive geopolitiche e promuovere una società più etica e inclusiva. Le Sonic Arts, ponendo l’ascolto al centro del contesto d’indagine, facilitano il dialogo interculturale, la giustizia acustica e l’emancipazione culturale, mentre si enfatizza la necessità di una ri-educazione all’ascolto, che sfrutti il suo potenziale terapeutico per una coesistenza globale più consapevole e inclusiva.

Music and sounds evoke a wide range of emotions and activate numerous psychological and physiological effects. Since emotions involve the autonomic nervous system (ANS) associated with the maintenance of homeostasis, they play an important role in supporting human wellbeing. The aim of the present study is to further validate the mechanisms underlying the relationship between sound, emotions and homeostasis. To this end, the effects of spatial sound projection of two different singing bowls with fundamental frequencies at 73 Hz and 110 Hz were investigated by monitoring behavioural and emotional response in healthy subjects. Overall, we find that the spatial projection of singing bowl sounds elicits a highly significant increase in positive emotions. Exposure to both frequencies resulted in a significant improvement in emotional wellbeing and a significant reduction in negative emotions. We demonstrate frequencydependent effects indicating a shift in arousal, where 73 Hz elicits feeling more wide awake while 110 Hz elicits sleepiness. These results indicate that non-invasive interventions, such as sound immersion with singing bowls, are effective means in restoring and maintaining homeostasis and underline the need for further research on the effect of discrete frequencies on human psychology and physiology, opening new perspectives on potential treatment of various disorders and conditions.

Music and sounds activate numerous physiological effects associated with the functioning of the autonomic nervous system and involved in the maintenance of homeostasis. As such, sound interventions can play an important role in supporting human wellbeing. Physiological responses are dependent on the sound type and frequency, as well as the spatial conditions and the presence of the subject in the acoustic environment. To arrive at a more articulate understanding of these dependencies, response of subjects (n=44) to sound reproduction of two different singing bowls with fundamental frequencies at 73 Hz and 110 Hz in spatial projection of nine different geometric shapes were monitored by acoustic and physiological measurement. Contrary to other studies, we find no discrete effects related to the sound type or frequency. Observed effects indicating focused attention, relaxation and improved homeostasis were consistently dependent on the combination of sound frequency and spatial condition. Notably, we observe that the 73 Hz stimulus induced significant changes in the Gamma band of Electroencephalography (EEG) in projection of a Tetrahedron and Cube, while the 110 Hz stimulus induced significant changes in the Theta and Beta bands for the same shapes. Discrete effects of spatial shapes were observed in the Galvanic Skin Response (GSR) of subjects. Arousal was significantly decreased during projection of a Cube, Icosahedron and Dodecahedron and significantly increased during Pyramid, Tetrahedron and Sphere, regardless of the frequency. Discrete effects of stimulus duration were observed in GSR and Electromyography (EMG) of subjects, regardless of the frequency and spatial condition. Arousal and muscle tension were significantly increased during the first 15 minutes and decreased until 40 minutes of exposure. We observe highly significant deviations in projected sound waves in the presence of a subject. The localized amplitude difference of sound waves was highly correlated to localization and power of significant changes in brain activity of subjects, while the phase shift of sound wave frequency was predictive of the frequency of brain activity. Significant expressions of Heart Rate (HR) and Heart Rate Variability (HRV) of subjects were highly correlated to the mean, variability and standard deviation of amplitude difference and phase shift of the fundamental frequency and the average across frequencies. We present a model in the form of a transfer function that accurately predicts various physiological expressions in response to sound stimuli on the basis of observed sound wave deviations. We discuss the benefits of such a model and the future work necessary to develop the model to its full predictive capacity.

The effects of sound and mechanical vibrations on blood flow and in vitro and in vivo blood cells were previously reported in various studies. Frequency-based stimulation and sound vibrations were shown to have a positive effect on peripheral blood flow, blood aggregation, Red Blood Cells longevity and enhanced release of Nitric Oxide which supports improved blood oxygenation. Different frequencies were also reported to have discrete effects on cells and physiological mechanisms. In this preliminary study, we investigated the effect of 20 minutes exposure to audible sound stimuli comprising recordings of spatial sound projections of a singing bowl at 40 Hz and 73 Hz compared to 20 minutes silence in a Faraday cage (control) on in vitro Red Blood Cells and White Blood Cells. We find that the sound stimuli have a highly significant effect on the longevity of both Red and White Blood Cells with a differentiation in effect across frequencies and projections compared to control. Results could indicate a cost-effective treatment to support improved soundness of blood transfusions as well as non-invasive interventions to increase circulating blood cells.

Sound waves are known to be affected by the presence of a human subject in the acoustic environment. Deviations in sound waves are dependent on the position, posture and body mass of the subject, and show consistent variance dependent on the subject and the sound stimulus. To arrive at a better understanding of the nature of this dependency, deviations in sound waves in the presence of a human subject were measured in an acoustic test environment, in conjunction with measurements reporting the physiological and psychological state of subjects in response to a sound stimulus projected in three different room sizes. We find that the absorption or amplification of sound waves in response to the subject is directly proportional to the amplitude of brain activity of the subject, where the amplification of both sound waves and brain activity is associated with an increase in positive valence and decrease in negative valence experienced by the subject. Increased Theta activity corresponded to a strong increase in harmonic power of low sound frequencies in the medium room size, while increased Gamma activity observed in the right parietal lobe indicates an enhanced spatial perception of subjects in this projection. We discuss the potential of these findings for future research and applications.

Nonlinear standing waves known as Faraday waves are formed in vibrating liquids enclosed by a container. In an effort to further our understanding of the relation between frequency and wave propagation within spatial boundaries we present a taxonomy to classify the variety of the observed resonant phenomena. This taxonomy includes some new definitions and suggests a unified language for describing wave propagation phenomena. We investigated the observed resonant phenomena and complex nonlinear dynamics utilising the Cymascope instrument, which works by transposing sound periodicities to water molecule periodicities.