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Making noise : making sounds
This book explains how sounds are made through a variety o f easy-to-understand examples and hands-on experiments.
Book
The Psychophysical Ear
In the middle of the nineteenth century, German and Austrian concertgoers began to hear new rhythms and harmonies as non-Western musical ensembles began to make their way to European cities and classical music introduced new compositional trends. At the same time, leading physicists, physiologists, and psychologists were preoccupied with understanding the sensory perception of sound from a psychophysical perspective, seeking a direct and measurable relationship between physical stimulation and physical sensation. These scientists incorporated specific sounds into their experiments--the musical sounds listened to by upper middle class, liberal Germans and Austrians. In The Psychophysical Ear, Alexandra Hui examines this formative historical moment, when the worlds of natural science and music coalesced around the psychophysics of sound sensation, and new musical aesthetics were interwoven with new conceptions of sound and hearing. Hui, a historian and a classically trained musician, describes the network of scientists, musicians, music critics, musicologists, and composers involved in this redefinition of listening. She identifies a source of tension for the psychophysicists: the seeming irreconcilability between the idealist, universalizing goals of their science and the increasingly undeniable historical and cultural contingency of musical aesthetics. The convergence of the respective projects of the psychophysical study of sound sensation and the aesthetics of music was, however, fleeting. By the beginning of the twentieth century, with the professionalization of such fields as experimental psychology and ethnomusicology and the proliferation of new and different kinds of music, the aesthetic dimension of psychophysics began to disappear.
eBook
Experimental study on sound radiation time-frequency characteristics of double cylindrical shell based on EMD
Purpose - Laying the acoustic decoupling material on the surface of underwater structures is an effective noise reduction technology. The underwater sound radiation experiment of finite stiffened double cylindrical shell with separate-sound and decoupled tile is carried out with the aim of finding out the most effective laying condition.Design methodology approach - The segmentation power function interpolation method and vertex extreme value envelope continuation method are introduced into basic theory of empirical mode decomposition (EMD). The original measured sound pressure signals are decomposed to intrinsic mode function (IMF) group through EMD, and the high-frequency components are filtered out. Because the mechanical noise of submarine is mainly at low frequency, the IMFs in low frequency are researched through power spectrum analysis. The noise reduction effects of different separate-sound and decoupled tile laying conditions are compared.Findings - The sound pressure signal components' amplitudes, periods and phases are obtained through EMD. The test data show that the double cylindrical shell entirely covered with separate-sound and decoupled tile is the most effective laying condition in noise reduction.Originality value - With reference to the case study, this is believed to be the first application of the EMD in sound radiation time-frequency characteristics of double cylindrical shell. The evaluation of separate-sound and decoupled tile laying conditions is of great importance in engineering applications.
Journal Article
Reciprocal sound transmission measurement of mean current and temperature variations in the central part (Aki-nada) of the Seto Inland Sea, Japan
A 30 km-range reciprocal sound transmission experiment was carried out on the line connecting Honshu and Shikoku (the first and fourth biggest main Japanese islands, respectively) in the central part (Aki-nada) of the Seto Inland Sea, Japan, during March–May 2010 to measure the mean current and temperature variations over the sea. The range-averaged current along the sound transmission line was estimated to have a mean and standard deviation of (3.8–4.4) ± (1.7–1.8) cm/s after converting the travel time difference data into currents, including a fortnightly tidal variation in the range of ±30 cm/s. The positive mean current implies slow water movement from the west to east through Aki-nada. The range-averaged speed of sound was estimated by converting from the mean travel time or one-way travel time into the speed of sound, and further converted into temperature for fixed values of salinity and depth, according to the standard speed of sound formula. Besides the precise measurement (to an accuracy of 0.01°C) of semidiurnal and diurnal tidal variations and seasonal warming, the temperature data showed periodic variations with periods of 7.0 and 21.1 days that had never been observed in Aki-nada before. This study suggests that reciprocal sound transmission is a powerful technique for the long-term accurate measurement of mean current and temperature variations in coastal and inland seas.
Journal Article
Extraction and Quantitation of Phytosterols from Edible Brown Seaweeds: Optimization, Validation, and Application
Brown seaweeds are known as important marine food sources, from which phytosterols have been recognized as functional food components with multiple health-beneficial effects. However, studies on phytosterol extraction and quantitation from edible brown seaweeds are limited. In the present work, extraction methods for seaweed phytosterols were compared and optimized by one-factor-at-one-time method and response surface methodology. Moreover, the quantitation method of total sterols and major sterol components, including fucosterol, saringosterol, and ostreasterol, was established and validated using 1H NMR. Furthermore, the developed extraction and determination methods were applied to investigate three common edible seaweeds from Japan (Hijiki, Wakame, and Kombu). As a result, the finally optimized conditions were ultrasound-assisted extraction with CHCl3-MeOH 2:3 for 15 min followed by saponification with 1.65 mL of 1.85 M KOH for 14.5 h. Based on the developed methods, phytosterols in three seaweeds were compared, and Hijiki showed an abundant total sterol amount (2.601 ± 0.171 mg/g DW), significantly higher than Wakame (1.845 ± 0.137 mg/g DW) and Kombu (1.171 ± 0.243 mg/g DW). Notably, the composition of the sterol components varied in different seaweeds. These findings might help the nutritional investigation and functional food development concerning phytosterols from seaweeds.
Journal Article
Has Predation Shaped the Social Systems of Arboreal Primates?
I studied antipredator behavior in two species of monkeys to elucidate the role of predation in shaping the social systems of arboreal primates. I compared the responses of monkeys to auditory and visual contact with predators to response elicited by sound playback experiments using the recorded calls of predators. Changes in vigilance and aggregation persisting up to 30 min after predator encounter occurred in both cases. Measures of vigilance shed light on individual perceptions of risk, while aggregation measures--intragroup spatial cohesion and polyspecific associations--permit direct inference about the protective benefits of grouping for the monkeys. They responded to real predator encounters and simulations in similar ways. Thus, sound playbacks of predator vocalizations are effective to simulate predator proximity. Contrary to predictions, predator encounters did not lead invariably to increased cohesion within groups or to increased time spent vigilant. Moreover, behavior in polyspecific associations was no different from that in single-species groups. Only red colobus encountering chimpanzees behaved as predicted by increasing vigilance and intragroup cohesion. The red colobus social system may have developed to protect against chimpanzee attack. In contrast, red-tailed monkey encounters with raptors and chimpanzees involved no change in time spent vigilant, coupled with decreases in intragroup cohesion. I conclude that predation is not a uniform selective pressure and patterns of social behavior within groups do not predict antipredator behavior. [PUBLICATION ABSTRACT]
Journal Article
Rise of the machines: Integrating technology with playback experiments to study cetacean social cognition in the wild
Cetaceans represent an evolutionary peak in terms of their cognitive capacities, complex communication systems and their structured, multilevel societies. However, the difficulty of observing their behaviour underwater means that studying whale and dolphin sociality in the wild poses some significant methodological challenges. Traditionally, playback experiments have been used to explore aspects of communication and cognition in whales and dolphins, particularly with trained animals under human care. However, while these studies have provided major breakthroughs in our understanding of cetacean social cognition, it is difficult to know whether these findings generalize to wild animals. In recent years, new state‐of‐the‐art technology (drones and non‐invasive sound and movement tags) have revolutionized the field of marine mammal behaviour, providing unparalleled information on the fine‐scale behaviour of individuals in the wild. Here, we review the state of the field, combining published studies with our own extensive experience, to demonstrate how these new technologies fundamentally change the behavioural metrics that we are able to measure; allowing us to move from categorical observations to quantifying fine‐scale changes in movement, activity and vocal behaviour. We discuss how conducting playback experiments alongside these new technologies combines rigorous experimental design with strong ecological validity and increased reproducibility and can be adapted for many social species, setting the standard for high‐calibre, field‐based experiments that explore animal social cognition in the wild.
Journal Article
Effects of Soundscape Complexity on Urban Noise Annoyance Ratings: A Large-Scale Online Listening Experiment
Noise annoyance has been often reported as one of the main adverse effects of noise exposure on human health, and there is consensus that it relates to several factors going beyond the mere energy content of the signal. Research has historically focused on a limited set of sound sources (e.g., transport and industrial noise); only more recently is attention being given to more holistic aspects of urban acoustic environments and the role they play in the noise annoyance perceptual construct. This is the main approach promoted in soundscape studies, looking at both wanted and unwanted sounds. In this study, three specific aspects were investigated, namely: (1) the effect of different sound sources combinations, (2) the number of sound sources present in the soundscape, and (3) the presence of individual sound source, on noise annoyance perception. For this purpose, a large-scale online experiment was carried out with 1.2k+ participants, using 2.8k+ audio recordings of complex urban acoustic environments to investigate how they would influence the perceived noise annoyance. Results showed that: (1) the combinations of different sound sources were not important, compared, instead, to the number of sound sources identified in the soundscape recording (regardless of sound sources type); (2) the annoyance ratings expressed a minimum when any two clearly distinguishable sound sources were present in a given urban soundscape; and (3) the presence (either in isolation or combination) of traffic-related sound sources increases noise annoyance, while the presence (either in isolation or combination) of nature-related sound sources decreases noise annoyance.
Journal Article
Analysis of Mesoscale Eddy Effects on Sound Wave Propagation Using the Bellhop Model
This study focuses on a mesoscale eddy in the South China Sea, analyzing its intensity, size, and temperature-salinity structure using reanalysis data. Two sets of experiments were conducted using the Bellhop acoustic model to simulate the propagation of sound waves from inside the eddy to the outside and vice versa. In each set of experiments, control experiments were also performed to investigate the impact of the mesoscale eddy on sound propagation. The results indicate that when the sound source is located at 50 m below the surface and propagates outward from the eddy center, the warm eddy causes an expansion of the surface channel radius by 22 km. For sound sources at 150 m and 250 m below the surface, the warm eddy weakens the acoustic energy, causing the convergence zone to shift forward, with the depth of the convergence zone increasing as the propagation distance increases. When the sound source is located at 50 m below the surface and propagates inward from outside the eddy, the warm eddy causes the surface channel to disappear. For sound sources at 150 m and 250 m below the surface, the warm eddy slightly shifts the convergence zone forward, with a significant decrease in the depth of the convergence zone. Finally, error comparison experiments were conducted to validate the rationality and rigor of the experimental setup.
Journal Article
Can you hear me? Playback experiment highlights detection range differences between commonly used PAM devices: C-POD, F-POD and SoundTrap
Passive acoustic monitoring (PAM) is a valuable tool for monitoring acoustically active small cetaceans such as the harbour porpoise ( Phocoena phocoena ), with a range of devices commonly used across studies. However, to ensure comparability of findings, there is a need to compare the ability of devices to detect acoustic signals. Using a playback approach, we determined the detection probability and effective detection radius/area (EDR/EDA) for co-deployed C-POD (Cetacean POrpoise Detectors), F-POD (Full waveform capture POD) and SoundTrap acoustic monitoring devices. We conducted playbacks of harbour porpoise recordings across two transects at a range of distances from moored devices, while accounting for a range of variables likely to influence the detection probability of playbacks. Distance from the devices influenced the detection probability across all devices, and a significant difference between transects was also found for the C-POD, possibly due to different ambient noise conditions. The maximum detection distance of the playbacks for the SoundTrap and the F-POD was between 400 - 500m, and EDR was estimated at 297m (EDA 0.276 km 2 ) and 241m (EDA 0.181 km 2 ), respectively. The maximum detection distance for the C-POD was lower, at 300 - 400m, and an EDR of 220m (EDA 0.153 km 2 ). A lower EDR was calculated for harbour porpoise buzzes compared to clicks across devices, due to lower source level of buzzes, suggesting that time spent foraging may be underestimated in PAM studies. The results highlight how detection ranges may differ across commonly used PAM devices, affecting comparability of detection rates across studies. EDR/EDA is an important prerequisite for PAM-derived density and abundance estimates. As such, understanding how devices differ is essential for comparing studies and appropriate planning of long-term acoustic monitoring projects, particularly where estimates of abundance are a key goal.
Journal Article