scholarly journals Vocalization with semi-occluded airways is favorable for optimizing sound production

2021 ◽  
Vol 17 (3) ◽  
pp. e1008744
Author(s):  
Ingo R. Titze ◽  
Anil Palaparthi ◽  
Karin Cox ◽  
Amanda Stark ◽  
Lynn Maxfield ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Free Space ◽  
Sound Production ◽  
Sound Quality ◽  
Acoustic Signals ◽  
Ct Scans ◽  
Acoustic Source ◽  
Impedance Calculation ◽  
Geometric Measurement ◽  
Airway Dimensions

Vocalization in mammals, birds, reptiles, and amphibians occurs with airways that have wide openings to free-space for efficient sound radiations, but sound is also produced with occluded or semi-occluded airways that have small openings to free-space. It is hypothesized that pressures produced inside the airway with semi-occluded vocalizations have an overall widening effect on the airway. This overall widening then provides more opportunity to produce wide-narrow contrasts along the airway for variation in sound quality and loudness. For human vocalization described here, special emphasis is placed on the epilaryngeal airway, which can be adjusted for optimal aerodynamic power transfer and for optimal acoustic source-airway interaction. The methodology is three-fold, (1) geometric measurement of airway dimensions from CT scans, (2) aerodynamic and acoustic impedance calculation of the airways, and (3) simulation of acoustic signals with a self-oscillating computational model of the sound source and wave propagation.

Numerical Simulation of the Buried Object Detection Based on Underwater Plasma Acoustic Source

2011 ◽  
Vol 105-107 ◽  
pp. 80-83
Author(s):  
Jun Zhang ◽  
Xin Wu Zeng ◽  
Yi Bo Wang ◽  
Zhen Fu Zhang ◽  
Dan Chen
Keyword(s):  
Wave Propagation ◽  
Object Detection ◽  
Pulse Length ◽  
Low Frequency ◽  
Basic Mechanism ◽  
Propagation Model ◽  
Staggered Grid ◽  
Acoustic Source ◽  
Buried Objects ◽  
Buried Object

Detection and classification of buried objects is of great importance in underwater counterterrorism and archaeology. To penetrate the sediment, a low frequency intensive acoustic source is needed. Underwater plasma acoustic source (UPAS) with high voltage discharge has the advantage of adjustable pulse length, high source level output and no pollution to the environment, which can satisfy these needs. In this paper, we introduced the UPAS, including its basic mechanism, structure and pressure output. Then we build up an elastic wave propagation model, solved it with finite difference and staggered grid methods, and combined with certain source and boundary condition, we simulated and analyzed the pressure wave propagation in time domain with an aluminum cylinder buried in sediment, from the results we validated the effectiveness of UPAS in the application of buried object detection.

Sound Quality

2020 ◽  
pp. 67-80
Author(s):  
Mads Walther-Hansen
Keyword(s):  
Cognitive Processing ◽  
User Interfaces ◽  
First Generation ◽  
Sound Production ◽  
Sound Quality ◽  
Cognitive Sciences ◽  
Visual Metaphors ◽  
Language Technology ◽  
The World ◽  
Source Of Information

The chapter takes a closer look at sonic concepts and the relevant major strands of research in the cognitive sciences. The chapter explores the ways in which the cognitive processing of sound is a multimodal task that extends into the world via language, technology, and actions. The main source of information in this study consists of cognitive metaphors reflected in written accounts, but the chapter also outlines nonlinguistic realizations of sound quality such as visual metaphors (e.g., graphical user interfaces) and enacted metaphors (e.g., bodily actions). The transition from analog mixing boards to digital ones that maintain the actions and look of the first-generation models is explored in the context of the SIGNAL FLOW metaphor. Finally, the schematic function of force metaphors in sound production is covered.

scholarly journals A Novel Radio Wave Propagation Modeling Method Using System Identification Technique over Wireless Links in East Africa

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Solomon T. Girma ◽  
Dominic B. O. Konditi ◽  
Ciira Maina
Keyword(s):  
Wave Propagation ◽  
System Identification ◽  
Radio Wave ◽  
Free Space ◽  
Urban Areas ◽  
Radio Channel ◽  
Signal Propagation ◽  
Propagation Model ◽  
Radio Wave Propagation ◽  
Study Region

Transmission of a radio signal through a wireless radio channel is affected by refraction, diffraction and reflection, free space loss, object penetration, and absorption that corrupt the originally transmitted signal before radio wave arrives at a receiver antenna. Even though there are many factors affecting wireless radio channels, there are still a number of radio wave propagation models such as Okumura, Hata, free space model, and COST-231 to predict the received signal level at the receiver antenna. However, researchers in the field of radio wave propagation argue that there is no universally accepted propagation model to guarantee a universal recommendation. Thus, this research is aimed at determining the difference between the measured received signal levels and the received signal level calculated from the free space propagation model. System identification method has been proposed to determine this unknown difference. Measured received signal levels were collected from three randomly selected urban areas in Ethiopia using a computer, Nemo test tool, Actix software, Nokia phone, and GPS. The result from the simulations was validated against the received experimental signal level measurement taken in a different environment. From the simulation results, the mean square error (MSE) was 4.169 dB, which is much smaller than the minimum acceptable MSE value of 6 dB for good signal propagation, and 74.76% fit to the estimation data. The results clearly showed that the proposed radio wave propagation model predicts the received signal levels at 900 MHz and 1800 MHz in the study region.

Spectromorphological analysis of sound objects: an adaptation of Pierre Schaeffer's typomorphology

2007 ◽  
Vol 12 (2) ◽  
pp. 129-141 ◽  
Author(s):  
Lasse Thoresen ◽  
Andreas Hedman
Keyword(s):  
New World ◽  
Sound Production ◽  
Sound Quality ◽  
Electroacoustic Music ◽  
Western Music ◽  
Avant Garde ◽  
Practical Tool ◽  
Practical Analysis ◽  
Sound Objects ◽  
The 1960S

AbstractThe last fifty years has witnessed an enormous development with regard to sound production, and has opened a new world of novel aural experiences. In order to be able to articulate and discuss these experiences there is a need for a corresponding novel set of terms and concepts. Such a terminology would also be relevant for analytical and interpretive approaches to electroacoustic music, avant-garde Western music, and ethno music. Pierre Schaeffer's typomorphology, developed in the 1960s, proposed a variety of novel terms, but they have not been of widespread use, since they unfortunately did not lend themselves very well for practical analysis. The present paper intends to develop Schaeffer's approach in the direction of a practical tool for conceptualising and notating sound quality. While carefully reducing the sometimes-bewildering number of terms found in Schaeffer's work, it introduces a set of graphic symbols apt for transcribing electroacoustic music in a concise score. The analysis of sound objects calls for a specific listeners' intention, called reductive listening.

scholarly journals ANOMALOUS SEISMO-ACOUSTIC WAVE PROPAGATION AND DETERMINATION SOURCE OF INFRASOUND

2017 ◽  
pp. 29-35
Author(s):  
Bayarsaikhan Ch ◽  
Tungalag L ◽  
Lkhagvajav Ch ◽  
Alexis Le Pichon
Keyword(s):  
Wave Propagation ◽  
Acoustic Wave ◽  
Frequency Analysis ◽  
Acoustic Signals ◽  
General Analysis ◽  
Acoustic Wave Propagation ◽  
Speed Distribution ◽  
Wide Range ◽  
Seasonal Wind

The network of infrasound stations (I34MN) in Mongolia daily registers set of infrasound from various sources besides explosions. The data from explosions in mines in region and from other sources detected since 2000 to 2009 in seismic and infrasound stations is analyzed. The analysis these signals dependence of speed distribution of sound from seasonal, wind forces and direction moreover on short distances. From detected in infrasound stations (I34MN) in year 80-90 % of signals make microbaroms, the wide range of their sources is visible from the frequency analysis. From the general analysis registered seismo and acoustic signals of explosions on the seismic and infrasound networks stations miscalculate not only speeds of distribution of sounds on close distances (50-500 km),  and also the speed model of atmosphere is made.

scholarly journals Wing, tail, and vocal contributions to the complex acoustic signals of courting Calliope hummingbirds

2011 ◽  
Vol 57 (2) ◽  
pp. 187-196 ◽  
Author(s):  
Christopher James Clark
Keyword(s):  
Sound Production ◽  
Low Frequency ◽  
Acoustic Signals ◽  
Wingbeat Frequency ◽  
Physical Mechanisms ◽  
Frequency Tone ◽  
Single Mechanism ◽  
Sound Pulses ◽  
Stellula Calliope ◽  
Courtship Displays

Abstract Multi-component signals contain multiple signal parts expressed in the same physical modality. One way to identify individual components is if they are produced by different physical mechanisms. Here, I studied the mechanisms generating acoustic signals in the courtship displays of the Calliope hummingbird Stellula calliope. Display dives consisted of three synchronized sound elements, a high-frequency tone (hft), a low frequency tone (lft), and atonal sound pulses (asp), which were then followed by a frequency-modulated fall. Manipulating any of the rectrices (tail-feathers) of wild males impaired production of the lft and asp but not the hft or fall, which are apparently vocal. I tested the sound production capabilities of the rectrices in a wind tunnel. Single rectrices could generate the lft but not the asp, whereas multiple rectrices tested together produced sounds similar to the asp when they fluttered and collided with their neighbors percussively, representing a previously unknown mechanism of sound production. During the shuttle display, a trill is generated by the wings during pulses in which the wingbeat frequency is elevated to 95 Hz, 40% higher than the typical hovering wingbeat frequency. The Calliope hummingbird courtship displays include sounds produced by three independent mechanisms, and thus include a minimum of three acoustic signal components. These acoustic mechanisms have different constraints and thus potentially contain different messages. Producing multiple acoustic signals via multiple mechanisms may be a way to escape the constraints present in any single mechanism.

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