Use Of Acoustic Signals Research Articles

The stomatopod rumble: Low frequency sound production in Hemisquilla californiensis

Stomatopods (mantis shrimp), numbering over 450 species, are renowned for their exceptional visual and chemosensory abilities and yet virtually nothing is known about their use of acoustic signals. We present acoustic recordings and analyses of the sounds of a stomatopod, Hemisquilla californiensis. This species generates tonal, low frequency sounds, which we term ‘rumble’, that are spectrally similar to those produced by African and Asian elephants. The fundamental frequency of the stomatopod rumble ranges from 20 to 60 Hz, with a strong second harmonic. Hemisquilla californiensis appears to generate these sounds through contractions of the posterior mandibular remotor muscle which is coupled to a stiff, lateral extension of the carapace. The sides of the carapace are covered by large, polarized, red spots which vibrate during sound production. Thus, the animals may generate a multi-modal signal by coupling vibrational and visual signals. Hemisquilla californiensis generates the rumble while interacting with potential predators and burrow intruders, suggesting a defensive or territorial function for the sound.

The Evolution of Aural Acoustic-Immittance Measurements

The Evolution of Aural Acoustic-Immittance Measurements

Aiming at an Advanced Use of Acoustic Signals

Aiming at an Advanced Use of Acoustic Signals

A test of the "dear enemy effect" in the strawberry dart-poison frog ( Dendrobates pumilio )

Some territorial animals exhibit a form of social recognition, commonly termed the "dear enemy effect", in which territory residents display lower levels of aggression toward familiar neighbors compared to unfamiliar individuals who are non-territorial "floaters". Despite the widespread occurrence of territorial social systems and use of acoustic signals for communication in anuran amphibians, only two previous studies have demonstrated vocally mediated dear enemy behavior in a territorial frog. In this study, I conducted neighbor-stranger discrimination playback experiments in a third species of territorial frog, the strawberry dart-poison frog, Dendrobates pumilio (Anura, Dendrobatidae). In the first experiment (n=24), I broadcast the calls of a subject's nearest neighbor and the calls of an unfamiliar individual from the approximate midpoint between the subject's and the neighbor's territories. Although males responded to the stimuli, they did not exhibit differential responses to the calls of neighbors and strangers. In a second experiment (n=22), I broadcast the calls of a neighbor and a stranger to subjects through a speaker located in the approximate center of the neighbor's territory. Males also responded to the playback, although less intensely than in the first experiment, but no discrimination between the calls of neighbors and strangers was found. Thus, territorial males of the strawberry dart-poison frog appear not to discriminate behaviorally between the advertisement calls of neighbors and strangers. Several proximate and ultimate-level hypotheses for this lack of vocally mediated neighbor-stranger discrimination are discussed.

Application of optical ray tracing techniques to the simulation of sonar images

Optical ray tracing permits realistic simulations of light images to be produced by calculating the intensity and color of each individual light ray that is projected into a predefined scene. This paper presents a similar technique for the simulation of sidescan sonar images of under- water environments that are generated by the use of acoustic signals. The inherent properties of light in air and sound in an underwater envi- ronment produce several fundamental differences between the two tech- niques, mainly as a result of the temporal display of the sonar images. This paper investigates these differences, presents the basic methodol- ogy of the sonar simulation model, and illustrates the techniques used to circumvent the time-based display problems. Finally, some results ob- tained using this technique are presented. © 1997 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(97)02006-0)

Length measurement and stabilization of optical substrates

The initial work on the use of acoustic signals to feedback control the length of an optical substrate to the order of 10(-6) parts in 10(6) is described.

Using Insect Sounds to Estimate and Monitor Their Populations

Accurate estimates of population size are needed to understand the population dynamics of any species. They are also needed to determine when to implement a specific control tactic, and to measure whether that control tactic has been effective. This paper discusses the use of acoustic signals produced by insects and the feasibility of using these signals to census populations. Insect sounds are either incidental (produced as a by-product of some activity) or non-incidental (produced to cause a response in some other animal). Incidental sounds differ from non-incidental sounds with respect to several features that are important to using sound to census populations. These features include species specificity, frequency content, ease of localization, distance traveled, and the duration and timing of sound production. Studies of crickets show that information about which individuals in a population are producing sound, when the individuals produce sound (seasonally and daily), and the probability that individuals produce sound during census periods must be known to accurately estimate the size of a population.

Acoustic Signals in the Homoptera: Behavior, Taxonomy, and Evolution

The use of acoustic signals in communication, both within and between species, occurs widely in the Insecta (2, 35, 36). The loud airborne sounds of many groups of Orthoptera and of the large cicadas among the Homoptera are well known (1). In these groups, where communication may take place be­ tween individuals at distances very much greater than their own body length, tympanal acoustic receptors are well developed (50, 66). Some small insects are known to produce low intensity sounds. Many more possess structures that appear to be sound-producing mechanisms, but which have never been properly investigated (26, 35, 36). In recent years consider­ able advances have been made in our knowledge and understanding of the use of sound signals by small insects. For example, in species of Drosophila, and probably also in many other small winged insects, very close range, pulsed signals between individuals of the same species are produced by low frequency wing vibrations. These may only be detected by other individuals, when in very close proximity to the signaller, by the use of a displacement receptor-in Drosophila the lightly balanced antennal arista (7). In order to communicate over longer distances small insects, because of the purely physical limitations of their size, would have to use very high frequency, or ultrasonic, sounds (49, 50). However, high frequency sounds are not suitable for communication in structurally complicated habitats dominated by plants (50). An alternative that has received much attention recently is the use

The role of chemoreception in sex recognition by male crickets: Acheta domesticus and Teleogryllus oceanicus

ABSTRACT. Contact chemoreception is important in female recognition by Teleogryllus oceanicus (Le Guillou) males. Antennal contact of female conspecifics, body regions, detached antennae and conditioned substrate elicited mostly courtship responses including courtship songs. Aggressive acts were produced only in response to male conspecifics. Male body regions, detached antennae and conditioned substrate elicited very few courtship or aggressive acts and no songs. This suggests that one or several communication modes, in addition to chemical communication, are necessary to elicit aggressive responses. Acheta domesticus (L.) males cannot rely upon chemical cues for recognition of either sex. Responses to conspecifics suggest that A. domesticus males produce aggressive acts immediately after antennal contact with either sex. Aggressive response to males usually persists, but response to females often switches to courtship. Responses to body regions, detached antennae, and conditioned substrate were few, with courtship and aggressive responses elicited by both male‐ and female‐generated stimuli. The importance of contact chemoreception in cricket communication is suggested by (1) failure of hexane‐washed antennae to elicit aggressive or courtship acts, and (2) males spending more time in contact with body regions and conditioned substrates than with corresponding controls. Lack of response to male or female odour‐laden air suggests that chemical signals are used by males only if directly contacted. Chemical and other signals supplement the obvious use of acoustic signals for intra‐ and intersexual communication in these crickets. The importance of multimodal communication in sex recognition is discussed.

Determination of the Orientation of a Vertical Fracture by Interference Tests

An analytic solution for the pressure distribution around a fractured well in a homogeneous, infinite reservoir is presented in terms of tabulated functions. This solution can be used to determine fracture orientation from interference tests. Introduction The advent of costly tertiary recovery programs has resulted in the need to determine flow patterns created by fractures intersecting wellbores. This requires a knowledge of the compass orientation and length of fractures. Several papers have discussed determination of fracture length by pressure analysis. However, methods for determining the compass orientation using pressure data have not received much attention. This paper pressure data have not received much attention. This paper discusses a method for determining the compass orientation using pressure data obtained at shut-in observation wells due to pressure data obtained at shut-in observation wells due to production or injection at the fractured well. production or injection at the fractured well. In 1960 Elkins and Skov reported a method for determining the orientation of natural fractures. They assumed the system of natural fractures to behave like an anisotropic system and used the classical line-source solution to analyze, pressure behavior. More recently, Pierce et al. demonstrated the use of pulse testing for calculating fracture length and orientation. Other studies on the determination of fracture orientation include (1) use of acoustic signals; (2) measurement of pressure response at observation wells during fracture initiation and propagation; and (3) use of inflation impression packers and television cameras.Even though the problem has been recognized for quite some time, no general method exists for determining pressure distribution in the area drained by a vertically fractured well. The objective of this paper is to present an analytic expression, in terms of simple tabulated functions, for the pressure distribution in a uniform, homogeneous, infinite reservoir drained by a vertically fractured well. This solution may be used to analyze pressure data in adjacent observation wells to determine fracture orientation in a manner analogous to standard interference tests. It also may be used to analyze test data obtained by pulsing a vertically fractured well. pulsing a vertically fractured well. Theory The mathematical model considered in this study is identical to the uniform-flux fracture examined by Gringarten et al. We assume that a single vertical fracture intersects a wellbore located in an infinite, homogeneous, porous medium (Fig. 1). The surface production rate is assumed to be constant and all the production is obtained by means of the fracture. Fluid enters production is obtained by means of the fracture. Fluid enters the fracture at the same rate per unit area of the fracture (uniform-flux fracture). JPT P. 73

Study of Nonlinear Acoustics for the Purpose of Processing Sophisticated Signals

Abstract : The work consists of two projects - one on the digital control of acoustic signals from an imaging array and the second on the use of acoustic signals to interrogate thermal images formed on an array of silicon bolometers. In the first project it has been shown that in contrast to the present systems where analog systems are used to control the arrays in acoustic imaging multilevel digital processing systems can be employed to provide for the scanning and focusing of these arrays. The net result is an increase in performance and flexibility of these systems with images in real time. In the second part of the program we have shown that propagating acoustic signals can be used to interrogate an array of silicon bolometers which contain a thermal image. The theoretical and experimental results comprise a foundation for the construction of the thermal imaging device of the type described. The device should outperform existing uncooled thermal imaging devices over a practical range of frequencies. (Author)

The quiet gray whale (Eschrichtius glaucus)

Studies conducted during the period December 22, 1964–March 7, 1965 near San Diego, California and at several locations in Baja California failed to confirm the use of acoustic signals by the gray whale. It is concluded that this cetacean rarely transmits subsurface sounds, and that it utilizes methods other than echolocation for navigation in shallower areas during the day.

Audible electric signals in industrial plants, and acoustical engineering

The paper is a plea for a wider use of acoustic signals in industrial plants. It is shown that much time is wasted by the officials, experts, and important employees in trying to locate each other. With loud acoustic signals installed throughout a plant, in the shops, yards, and offices, it becomes possible to locate any of a considerable number of men instantly, using a simple code call for each. Such calls could be given only imperfectly by pushing a button, and for this reason a special code calling instrument has been developed, which closes electric contacts automatically, after having been set for a desired combination. The actual conditions and the needs for acoustic signals are discussed in application to steel mills, shipyards, textile mills, printing establishments, coal mines, construction jobs, etc. It is shown that in addition to code calls, audible signals and particularly electric horns are used with advantage as extensions to telephone bells in noisy places, and also as warning signals for various purposes. The general scope of the forthcoming art of acoustic engineering is then discussed, and its importance is shown in design of theaters, churches, and large auditoriums; also in the installation of fog signals. The problem of measurement of sound intensity is then taken up and the available means and devices are described. It is also shown that sound waves may be directly photographed under proper conditions and the laws of their propagation studied. Attention is called to the importance of experimental and theoretical study of the modes of vibrations of diaphragms used in acoustic devices.