Picking up the hydrothermal whisper at Ischia Island in the Covid-19 lockdown quiet

In this paper, we analyse the seismic noise at Ischia Island (Italy) with the objective of detecting the hydrothermal source signals taking advantage of the Covid-19 quiescence due to lockdown (strong reduction of anthropogenic noise). We compare the characteristics of the background noise in pre-, during and post-lockdown in terms of spectral content, energy release (RMS) and statistical moments. The continuous noise is decomposed into two independent signals in the 1−2 Hz and 2−4 Hz frequency bands, becoming sharpened around 1 Hz and 3 Hz respectively in lockdown. We propose a conceptual model according to which a dendritic system of fluid-permeated fractures plays as neighbour closed organ pipes, for which the fundamental mode provides the persistent whisper and the first higher mode is activated in concomitance with energy increases. By assuming reasonable values for the sound speed in low vapor–liquid mass fraction for a two-phase fluid and considering temperatures and pressures of the shallow aquifer fed by sea, meteoric and deep hydrothermal fluids, we estimate pipe lengths in the range 200–300 m. In this scheme, Ischia organ-like system can play both continuous whisper and transients, depending on the energy variations sourced by pressure fluctuations in the hydrothermal fluids.

Controller of Register Combinations and Tone Keys for Pipe Organ

A pipe organ is a musical instrument that produces sound by driving pressurized air through the organ pipes selected from a keyboard called a manual. It is constructed from settled groups of pipes. Each group is composed of similar pipes with the same tone colour and loudness but different pitch. Such a group is called a rank. We have developed two electronic devices for upgrading the organ. The first device named Controller of Register Combinations is intended for storing rank combinations and pipe organ controlling. The second device named Controller of Tone Keys for pipe organ allows users to play the organ simultaneously on two separate keyboards. In this paper, we represent the purpose, scheme, and our realization of both devices. The correct functioning of the devices was proved by integrating them into a church organ. We have already equipped several church organs with our electronics, and they all work flawlessly. Feedback from the organists is excellent, as both Controller of Register Combination and Controller of Tone Keys make it easier for them to play. The success so far and the positive responses of the organists have encouraged us already to plan further improvements and upgrades of the organ electronics.

Testing Hearing

Testing Hearing: The Making of Modern Aurality argues that the modern cultural practices of hearing and testing have emerged from a long interrelationship. Since the early nineteenth century, auditory test tools (whether organ pipes or electronic tone generators) and the results of hearing tests have fed back into instrument calibration, human training, architecture, and the creation of new musical sounds. Hearing tests received a further boost around 1900 as a result of injury compensation laws and state and professional demands for aptitude testing in schools, conservatories, the military, and other fields. Applied on a large scale, tests of seemingly small measure—of auditory acuity, of hearing range—helped redefine the modern concept of hearing as such. During the twentieth and twenty-first centuries, the epistemic function of hearing expanded. Hearing took on the dual role of test object and test instrument; in the latter case, human hearing became a gauge by which to evaluate or regulate materials, nonhuman organisms, equipment, and technological systems. This book considers both the testing of hearing and testing with hearing to explore the co-creation of modern epistemic and auditory cultures. The book’s twelve contributors trace the design of ever more specific tests for the arts, education and communication, colonial and military applications, and sociopolitical and industrial endeavors. Together, they demonstrate that testing as such became an enduring and wide-ranging cultural technique in the modern period, one that is situated between histories of scientific experimentation and many fields of application.

Revisiting the evolution of deformation zones under platform conditions in the case study of the Kungur Ice Cave (Cis-Urals)

Observations in mining tunnels and caves allow to identify composition and development specifics of fault structures under subsurface conditions at various stages of geological history. Basing on the existing formation model of Kungur Ice Cave karst system, author examines the transformations of deformation zones, occurring in the mass of interlaid sulfate and carbonate rocks under platform conditions. Morphologic specifics of vertical structures ­– organ pipes, developed within one of the gypsum-anhydrite units, are defined by evolution stages of disjunctive faults, penetrating the entire rock mass of the Ice Cave. Point infiltration of surface waters and formation of a single channel, where rock softening and taluses from overlapping deposits gradually occur, are currently considered to be the initiators of pipe formation. At a later stage a sink forms on the surface, increasing the amount of water coming to the karsting mass. However, the size of debris in the talus, incommensurate with the pipe head, rounded arches of separate pipes, fragments of feeder channels, characteristic for artesian conditions of underground water circulation, faceted rock debris from overlapping deposits, specifics of wall structure all define the priority of pipe formation over grottos and cave galleries. Plastic properties of gypsum sediments and processes of their hydration define secondary modifications of pipe walls up to complete filling of the voids and formation of secondary pillars with subsequent renewed formation of vertical channels – significantly smaller in diameter and formed by infiltration waters when subject to corrosion.

Organ pipes and bodies with organs: Listening to De Quincey’s First Opium War essays

War is prominent in sound studies, yet the sonic dimensions of the Opium Wars remain understudied. Analysing essays on the First Opium War by the English Opium-Eater, Thomas De Quincey (1785–1859), this article explores the dense relationships between opium, empire and sound in nineteenth-century Britain. It brings the tropes of the pipe as connector and organ as musical instrument, body part and instrument of the body politic into dialogue with Deleuze and Guattari’s theorisation of the ‘Body without Organs’, and suggests how the empires of China and Britain and their opium-taking subjects could be imagined as violently sounding bodies.

Giant extraordinary transmission of acoustic waves through a nanowire

Wave concentration beyond the diffraction limit by transmission through subwavelength structures has proved to be a milestone in high-resolution imaging. Here, we show that a sound wave incident inside a solid over a diameter of 110 nm can be squeezed through a resonant meta-atom consisting of a nanowire with a diameter of 5 nm equal to λ/23, where λ is the incident acoustic wavelength, corresponding to a transmission efficiency of 500 or an energy densification of ~14,000. This remarkable level of extraordinary acoustic transmission is achieved in the absence of ultrasonic attenuation by connecting a tungsten nanowire between two tungsten blocks, the block on the input side being furnished with concentric grooves. We also demonstrate that these “solid organ pipes” exhibit Rayleigh end corrections to their effective longitudinal resonant lengths notably larger than their in-air analogs. Grooves on the output side lead to in-solid directed acoustic beams, important for nanosensing.