Physical models for the analysis of acoustical systems in biology

1979 ◽  
Vol 12 (1) ◽  
pp. 25-65 ◽  
Author(s):  
N. H. Fletcher ◽  
Suszanne Thwaites

One of the important problems of biophysics is to understand in detail the mechanisms by which animals produce acoustic signals, and the ways in which other animals, of the same or different species, detect and process these signals, through the masking effects of ambient noise, to extract their information content. At a primitive level this information relates simply to the presence of the other animal and perhaps to its proximity and direction. At the next level we find some sort of coding in the acoustic signal which identifies the species and perhaps the sex, and finally there is the whole range of information content and emotional overtone contained in a complex sound like human speech or music.

1974 ◽  
Vol 26 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Irene Klenbort ◽  
Moshe Anisfeld

The subjects were presented with active and passive sentences. For each sentence, they had to choose between two alternative implications. The pattern of choices indicates that in the passive the logical subject was interpreted by the subjects as the focal point of the information asserted by the sentence and as the carrier of overall responsibility for the sentential proposition. In contrast to the passive, there was no clear pattern of preferences for the active. The difference between the two voices was attributed to their markedness asymmetry, the passive being marked and the active unmarked. It is concluded that the active offers a neutral structure for conveying information; a structure available for use when one does not want to superimpose on the information content any stylistic or connotational implications. The passive, on the other hand, suggests special connotations in addition to the basic message.


2018 ◽  
Vol 30 (10) ◽  
pp. 3083-3099 ◽  
Author(s):  
Panagiotis Stamolampros ◽  
Nikolaos Korfiatis

Purpose Although the literature has established the effect of online reviews on customer purchase intentions, the influence of psychological factors on online ratings is overlooked. This paper aims to examine these factors under the perspective of construal level theory (CLT). Design/methodology/approach Using review data from TripAdvisor and Booking.com, the authors study three dimensions of psychological distances (temporal, spatial and social) and their direct and interaction effects on review valence, using regression analysis. The authors examine the effect of these distances on the information content of online reviews using a novel bag-of-words model to assess its concreteness. Findings Temporal distance and spatial distance have positive direct effects on review valence. Social distance, on the other hand, has a negative direct effect. However, its interaction with the other two distances has a positive effect, suggesting that consumers tend to “zoom-out” to less concrete things in their ratings. Practical implications The findings provide implications for the interpretation of review ratings by the service providers and their information content. Originality/value This study extends the CLT and electronic word-of-mouth literature by jointly exploring the effect of all three psychological distances that are applicable in post-purchase evaluations. Methodologically, it provides a novel application of the bag-of-words model in evaluating the concreteness of online reviews.


2014 ◽  
Vol 281 (1787) ◽  
pp. 20140480 ◽  
Author(s):  
Michelle J. Spierings ◽  
Carel ten Cate

Variation in pitch, amplitude and rhythm adds crucial paralinguistic information to human speech. Such prosodic cues can reveal information about the meaning or emphasis of a sentence or the emotional state of the speaker. To examine the hypothesis that sensitivity to prosodic cues is language independent and not human specific, we tested prosody perception in a controlled experiment with zebra finches. Using a go/no-go procedure, subjects were trained to discriminate between speech syllables arranged in XYXY patterns with prosodic stress on the first syllable and XXYY patterns with prosodic stress on the final syllable. To systematically determine the salience of the various prosodic cues (pitch, duration and amplitude) to the zebra finches, they were subjected to five tests with different combinations of these cues. The zebra finches generalized the prosodic pattern to sequences that consisted of new syllables and used prosodic features over structural ones to discriminate between stimuli. This strong sensitivity to the prosodic pattern was maintained when only a single prosodic cue was available. The change in pitch was treated as more salient than changes in the other prosodic features. These results show that zebra finches are sensitive to the same prosodic cues known to affect human speech perception.


2020 ◽  
Vol 15 (5) ◽  
pp. 729-737
Author(s):  
Gong Chen ◽  
Lei Cai ◽  
Lv Zong ◽  
Yan Wang ◽  
Xin Yuan

Passive acoustic technology (PAT) is an important tool to acquire the passive acoustic signals from marine organisms. In this paper, PAT fish detection is introduced at great length, including the relevant instruments, signal processing methods, and workflow. Focusing on the key tasks of PAT fish detection, the authors proposed a sparse decomposition algorithm that extracts coherent ratio of passive fish acoustic signal, and designed a feature extraction method for that signal based on speech imitation technology. Experimental results demonstrate that the proposed sparse decomposition algorithm can detect fish acoustic signal accurately at low signal-to-noise ratios (SNRs), and the proposed feature extraction method can effectively extract fish acoustic signals from the marine background. The research results shed important new light on the protection and management of fishery resources in the seas and oceans.


2016 ◽  
Vol 16 (6) ◽  
pp. 220-231
Author(s):  
Hong Kun Wang ◽  
Shou Xiang Wang ◽  
Jing Nie

Abstract With the formation of China’s large power grid, the security of the network is particularly important. The contaminant flashover of insulators has a serious impact on the operation safety of a high voltage power network. In this paper, the acoustic signals’ characteristics of the contaminant insulators flashover are analyzed, and, as a result, the correlation between the acoustic signal and the contaminant insulator flashover is established. To experiment with contaminant insulator for three different Equivalent Salt Deposit Densities (ESDD), acoustic signals were collected separately. Then, the contaminant insulators’ acoustic signals of flashover were analyzed by wavelet packet. The characteristics of the signals were obtained, and they can be judged for contaminant flashover warning.


Author(s):  
Таtiana М. Tkachenko ◽  
Yulia H. Pilkevich ◽  
Heorhii M. Rozorinov

The basic sources of contamination and obstruction of reservoirs are cleared not enough sewer water of industrial and communal enterprises, large stock-raising complexes, wastes of production; upcast of water and railway transport; wastes of roughing-out of flax, pesticides and other. Сontaminents, getting in natural reservoirs, result in the quality changes of water, that, mainly, appear in the change of physical properties of water, in the change of chemical composition of water, in a presence floating substances on the surface of water and laying of them on the bottom of reservoirs. The increases of population, expansion of old and origin of new cities considerably increased entering of domestic flows internal reservoirs. Synthetic cleansers that is widely used in the way of life contaminate reservoirs in a yet greater degree. In the total the capacity of waters goes down for oxigenating, activity of bacteria that mineralize organic substances is paralysed. The unfavorable ecological state of many freshwater ecosystems inflicts substantial harm to the fish resources of reservoirs and puts under a threat possibility not only to develop fish industry, conducting fish artificially, but also simply to catch her. All of it stimulate to do events in relation to the improvement of the ecological state of fresh reservoirs. Voice vibrations are the important constituent of the ecological monitoring of the biota state of fresh reservoirs. Information is about formation of sound in a reservoir part of that is activity of fishes turns out by means of acoustic sensors, that farther yields to computer treatment. The modern methods of recognition of fish acoustic patterns are based on the standards of signals, with properties of average estimations, or on comparisons of acoustic signals with a standard. It is shown that for creation of standards, as a rule, executed: previous signal processing, extraction of features of acoustic signal. Acoustic signals that act from movable objects – fishes can change depending on objective external terms and physical state of reservoirs. The hard algorithms of recognition of acoustic patterns are characterized high probability of error. In this connection repressing are adaptive algorithms of recognition of acoustic patterns. In the process of forming of standards clarification of software comes true according to the features of acoustic signal. Realization of process of creation of standards allows to determine the measure of functional readiness of parameters and knowledge base for the decision of recognition tasks of acoustic signals. In the process of recognition the probability terms of the correct comparing are set to the standard, on default of that an algorithm stops to be executed and requires additional studies. It requires creation of standards that reflect the characteristic features of fish signals. Presently for authentication mostly choose such pattern of acoustic signals, as period length of signal fundamental wave. It can be determined or by the search of maximal value in an autocorrelation function, or by the search of minimum value in the function of mean value of difference of signal amplitudes, or by the search of difference of two maximal values in the sequence of going into detail wavelet-coefficients. It is shown that for the tasks of recognition of fish acoustic patterns, most exact and requiring the least studies there is presentation of acoustic signal as a set of sign vectors of frames. In detail methodologies of the period selection of fundamental wave of acoustic signal were analysed: SIFT, EFT-А and EFT-WT. Methodology of EFT-WT is characterized absence of the thresholds set in good time; by the rapid search of period of fundamental wave; by absence of dependence on a noise-level, as a certain range of frequencies is investigated. At the same time calculable complication of wavelet transform is relatively high, in this connection it is necessary optimization of calculation algorithms.


2019 ◽  
Vol 8 (3) ◽  
pp. 2012-2016

This paper presents a novel technique for calculation of attenuation of acoustic signals in the materials in underwater channel. A laboratory procedure and algorithms have been developed for finding attenuation. In many applications like sonar signal processing acoustic signal attenuation in the dome or in an enclosure are required to be known. Finding the actual attenuation while signal passes through the materials is very useful in calculating the precise power transmitted through the enclosures. The attenuation in materials mainly dependent on type of material, signal frequency and launch angle of the signal. A proper procedure has been presented in this paper


1965 ◽  
Vol 2 (3) ◽  
pp. 201-219 ◽  
Author(s):  
Everett Mendelsohn

SynopsisThe response to physics and chemistry which characterized mid-nineteenth century physiology took two major directions. One, found most prominently among the German physiologists, developed explanatory models which had as their fundamental assumption the ultimate reducibility of all biological phenomena to the laws of physics and chemistry. The other, characteristic of the French school of physiology, recognized that physics and chemistry provided potent analytical tools for the exploration of physiological activities, but assumed in the construction of explanatory models that the organism involved special levels of organization and that there must, in consequence, be special biological laws.The roots of this argument about concept formation in physiology are explored in the works of Theodor Schwann, Johannes Müller, François Magendie and Claude Bernard among others.


2022 ◽  
Author(s):  
Wei-Wei Kan ◽  
Qiu-Yu Li ◽  
Lei Pan

Abstract The scattering behavior of the anisotropic acoustic medium is analyzed to reveal the possibility of routing acoustic signals through the anisotropic layers with no backscattering loss. The sound-transparent effect of such medium is achieved by independently modulating the anisotropic effective acoustic parameters in a specific order, and experimentally observed in a bending waveguide by arranging the subwavelength structures in the bending part according to transformation acoustics. With the properly designed filling structures, the original distorted acoustic field in the bending waveguide is restored as if the wave travels along a straight path. The transmitted acoustic signal is maintained nearly the same as the incident modulated Gaussian pulse. The proposed schemes and the supporting results could be instructive for further acoustic manipulations such as wave steering, cloaking and beam splitting.


Author(s):  
David Edward Jones ◽  
Chris Snider ◽  
Lee Kent ◽  
Ben Hicks

ABSTRACTWhile extensive modelling - both physical and virtual - is imperative to develop right-first-time products, the parallel use of virtual and physical models gives rise to two interrelated issues: the lack of revision control for physical prototypes; and the need for designers to manually inspect, measure, and interpret modifications to either virtual or physical models, for subsequent update of the other. The Digital Twin paradigm addresses similar problems later in the product life-cycle, and while these digital twins, or the “twinning” process, have shown significant value, there is little work to date on their implementation in the earlier design stages. With large prospective benefits in increased product understanding, performance, and reduced design cycle time and cost, this paper explores the concept of using the Digital Twin in early design, including an introduction to digital twinning, examination of opportunities for and challenges of their implementation, a presentation of the structure of Early Stage Twins, and evaluation via two implementation cases.


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