Sound Reception Research Articles

Influence of burrow acoustics on sound reception by frogsEupsophus (Leptodactylidae)

The effect of burrow acoustics on the reception of sounds by a leptodactylid frog, Eupsophus emiliopugini, from Southern Chile was investigated. Burrows occupied by E. emiliopugini males amplified vocalizations produced by conspecific individuals calling nearby and conspecific calls played back through a speaker positioned in the vicinity of the burrow by 5.2 dB ( N=4) and 4.3 dB ( N=5) on average, respectively. The spectral contents of calls recorded from inside burrows matched the resonant frequencies of the cavities measured with pure tones. Playback calls of a sympatric species, Batrachyla antartandica, which have spectra that do not overlap E. emiliopugini calls, were not amplified inside burrows to the same extent. Amplification of conspecific calls inside burrows may influence vocal interactions in chorusing assemblages of E. emiliopugini .

Active/passive technique for the creation of a low-frequency traveling wave inside a water-filled tube

Studies of sound reception in aquatic animals are often complicated by the problem of generating a suitable acoustic stimulus at low frequencies underwater. In this study, active and passive control techniques were used to generate a traveling acoustic wave inside a water-filled acrylic tube, at pure-tone frequencies from 10 to 800 Hz. The compliant walls of the tube reduced the wavelength and increased attenuation, both of which helped to reduce the amplitude of any reflected waves. Above 400 Hz, a traveling wave was present without any active control. Below 400 Hz, a secondary source was used to actively absorb sound at the tube end. The active control system consisted of two hydrophones, two sound projectors, and a personal computer with digital signal processing hardware. A simple pattern search algorithm was used to adjust the secondary source amplitude and phase in order to attain the desired acoustic impedance at the test location. This technique seems well suited for underwater sound tests on fish, since the relationship between pressure and particle velocity may be easily manipulated. [Work supported by ONR Grant No. N00014-94-1-0337.]

The tettigoniid (Orthoptera : Tettigoniidae) ear: Multiple functions and structural diversity

The ears of bushcrickets (Orthoptera : Tettigoniidae) consist of a pair of membranes situated beneath the knee of the foretibia. These membranes, or tympana, are backed by a tracheal system dedicated to sound reception. In most species, a trachea opens through a hole, the auditory spiracle, in the pleuron of the prothorax adjacent to the ventilatory spiracle. Experimental evidence clearly shows that in those species possessing such an opening, sound entering through this route is amplified by the shape of the trachea, or at least is modified through resonances created by its tracheal cavities or tubes. In some species the external surface of the tympanic membrane is surrounded by cuticular folds, which may be formed into small resonating cavities or sound guiding pinnae. In other species the tympana are naked. Sound interacts with the external surface of the tympana, either through these cuticular cavities or directly at the surface of the membrane. As with auditory tracheae, the shape of these cavities may modify sound through resonances. This review examines the role of both external and internal sound-guides in sound reception. It discusses how different species may utilize different sound receiving systems and suggests how, in some cases, both external and internal routes may respond to different frequency bands. The maximum sensitivity of the ear invariably coincides with the male's call carrier frequency. Two Australian species of tettigoniid where the ear is clearly not tuned to the male's call are described. The biology of one undescribed species belonging to the subfamily, Zaprochilinae, where not only is the ear untuned, but there is marked sexual dimorphism in ear structure, is elaborated on. The review concludes with an examination of the routes selection may have taken to arrive at the extreme morphologies present in the Tettigoniidae.

Die Mechanik und Funktion des Mittelohres - Teil 2: Hörphysiologische Anmerkungen zu Mittelohroperationen

The reconstruction of the destroyed ossicular chain has the purpose to re-establish an unhindered sound reception and transmission. With respect to the hydraulic factor, the reconstructed chain should be attached to a large effective area of the drum membrane, ideally to the malleus handle. The sensitivity is furthermore diminished in a linear relationship with increasing mass and stiffness. Therefore, cartilage cannot represent an acoustically ideal material for a drum membrane replacement. The reconstructed chain must vibrate without restraint for an unhindered transmission. Furthermore, the interposed prosthesis must be secured firmly to the remnants of the ossicular chain; the reconstructed chain must vibrate like one solid body. A loose contact attenuates the transmission and might result in a dislocation of the prosthesis with excessive ambient air pressure induced displacements of the drum membrane. A solid anchoring might be created by glueing, bony adhesion, special design of the prosthesis or with a wire connection. With unfavorable middle-ear conditions, the piston-like vibrational mode of the footplate has to be met with a direct driving of the stapes by a T-like prosthesis in the extension of the stapedial's vertical (high) axis. Ineffective rocking movements of the footplate are thus reduced. The almost perfect hearing result of the stapesplasty demonstrates that the impedance-matching middle-ear function is determined by the area ratio between the drum membrane and the width of the cochlear scala. Both components are not altered by the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

A novel hearing organ in an acoustic parasitoid fly

Female parasitoid flies (Ormiaochracea: Tachinidae) are attracted to singing male crickets [W. Cade, Science 190, 1312 (1975)]. Gravid female flies orient to calling crickets to deposit larvae, which burrow into the cricket in order to feed and grow to adulthood. To detect and locate cricket songs over long distances, these flies evolved a tympanal hearing organ previously unkown in flies. Electrophysiological recordings reveal low auditory thresholds (20 dB SPL between 4–6 kHz) matching the peak of the power spectrum of the host’s song (Gryllusrubens, 4.5–5 kHz). Such sensitivity is consistent with long distance hearing. The ear, composed of two adjacent thin tympanal membranes, contains two mechanoreceptive sensory organs that are both located in a single air-filled chamber. Laser vibrometry suggests that this tympanal arrangement provides a novel mechanism for directional sound reception. Some aspects of its vibratory behavior in a sound field will be reported. [Work funded by NINDCD-DC00103 and Hatch NYC-191403.]

Innervation of the amphibian and basilar papillae in the leopard frog: reconstructions of single labeled fibers.

Amphibians have two auditory organs specialized for reception of airborne sounds: the amphibian papilla and the basilar papilla. In this report we examine the morphology of the ganglion cells and the afferent innervation of the sensory epithelium in both auditory organs of the leopard frog, Rana pipiens pipiens. Extracellular injections of either biocytin or horseradish peroxidase (HRP) were made into the VIII nerve; they labeled ganglion cells, their axons, and their terminal fibers within the papillae. Ganglion cells that projected to either the amphibian papilla or basilar papilla had cell bodies that were morphologically distinct from other labeled cells. In the amphibian papilla thick fibers terminated in the rostral portion and thin fibers terminated in the caudal portion. Labeled fibers in the rostral portion traveled short distances before making contacts with up to nine hair cells whereas labeled fibers in the caudal portion traveled longer distances and contacted no more than five hair cells. In the basilar papilla labeled fibers were thick (around 4 microns) and terminated on as many as nine hair cells. Consistent with studies from the bullfrog, Rana catesbeiana, our results suggest that the amphibian papilla of R. pipiens pipiens has a convergent innervation (i.e., multiple hair cells provide input to a single ganglion cell) and is topographically organized. However, in contrast to reports in other ranid species, a highly convergent innervation like that found in the amphibian papilla is also found in the basilar papilla.

The Effects of Body Size on Functional Properties of Middle Ear Systems of Anuran Amphibians

Both tympanic and nontympanic pathways of sound reception are utilized by anuran amphibians. The relationship between body size and the acoustic responsiveness of various body surfaces that may serve as pathways for sound reception in anurans was analyzed. The motion of the different surfaces (tympanum, lateral body wall, lateral head surface, and dorsal shoulder surface) produced by sound was measured with a laser vibrometer in anuran species. The frequency response and amplitude levels of motion of these body surfaces clearly were linked with size. In all animals, nontympanic surfaces were most responsive to low frequencies, and the tympanum was most responsive to high frequencies. However, the responsiveness of nontympanic surfaces was greater, and extended to higher frequencies, in small anurans. In the smallest animals studied, nontympanic surfaces were often more responsive than the tympanum up to frequencies as high as 2500 Hz. In larger anurans, nontympanic responsiveness tended to decrease, and tympanic responsiveness tended to increase. In the largest animals studied, the tympanum was the most responsive surface at all except very low frequencies below about 200-300 Hz. These results suggest that small anurans can utilize nontympanic pathways for effective sound reception over a broad frequency range, whereas large anurans are more restricted to using a standard tympanic middle ear for hearing. This effect of body size on the utility of nontympanic sound reception may explain evolutionary patterns of tympanic ear reduction and loss observed in several small species of anurans.

Acoustics: Waves and Oscillations

Simple Harmonic Motion Theory of Forced Vibration and Resonance Theory of Coupled Oscillations Vibration in an Extended Medium Vibration of Strings Vibration of Bars Tuning Forks Vibration of Membranes and Rings Vibration of Air-Columns Transmission of Sound Reflection Refraction Interference and Diffraction of Sound Reception and Transformation of Sound Sound Measurement and Analysis Acoustics of Buildings Recording and Reproduction of Sound Ultrasonics Problems Index.

Sound Quality and Speech Reception for Prescribed Hearing Aid Frequency Responses

Four different prescriptions of hearing aid insertion gain versus frequency were validated with a group of 26 moderately hearing-impaired, elderly hearing aid users. Three prescriptions were based on calculating the loudness and articulation index (AI) for aided speech, and ranged from a frequency response with moderate high-frequency emphasis, restoring normal loudness for speech peaks, to a response with the greatest high-frequency emphasis, maximizing the AI. The fourth prescription was a well-established formula of the half-gain type. The frequency responses were evaluated by paired comparison ratings of the pleasantness and intelligibility of speech in noise, and by speech identification tests in noise. The subjects rated the flattest response as significantly more pleasant than the other responses, and significantly more intelligible than the prescription with maximal high-frequency emphasis. There were no detectable differences in signal/noise ratios required for 50% speech identification. These results indicate that a prescription that restores normal loudness for speech peaks in each critical band is probably more easily accepted than either a procedure which is intended to make all speech bands equally loud, or a prescription which maximizes the AI.

Acoustics, waves and oscillations

Simple Harmonic Motion Theory of Forced Vibration and Resonance Theory of Coupled Oscillations Vibration in an Extended Medium Vibration of Strings Vibration of Bars Tuning Forks Vibration of Membranes and Rings Vibration of Air-Columns Transmission of Sound Reflection Refraction Interference and Diffraction of Sound Reception and Transformation of Sound Sound Measurement and Analysis Acoustics of Buildings Recording and Reproduction of Sound Ultrasonics Problems Index.

Dance percussion platform

A tap dance platform for producing pitched sounds in response to energy imparted onto the surface of the platform having a flat base surface and parallel spaced-apart supports disposed on the flat base. Disposed on each of the spaced-apart supports are a plurality of flat spaced-apart keys which define a sound chamber between the base and the bottom of the keys. The supports are spaced-apart to engage the keys at their vibrational nodes. On the top surface of each of the spaced-apart supports are resilient strips to insulate the keys from the supports and the base to enhance the tonal sound. There are also provided side apertures in both the vertical supports and the side walls of the platform, to allow the sound to come out and to determine the desired sound quality. The ends of the platform are also recesses so that sound can travel out of each end of the platform. Thus, tap dancers can dance on the keys and create unique pitched, percussionlike sounds resembling a marimba.

A study on sound reception with spatial separability based on Kirchhoff's integral equation : How to obtain optimum characteristics of a super close-talking microphone

A study on sound reception with spatial separability based on Kirchhoff's integral equation : How to obtain optimum characteristics of a super close-talking microphone

In-The-Canal Hearing InstrumentsBenefits and Problems for Inexperienced Users Given Minimal Instruction

The number of in-the-canal hearing instruments (ITC) distributed annually in our region is increasing. The purpose of this investigation, which included 300 persons, was to evaluate the problems and benefits reported by ITC users who had received a minimum of counselling. Another aim was to decide which factors to concentrate on when teaching local health personnel how to assist hard-of-hearing equipped with ITC. The results showed that 38% had operational difficulties, 63% had experienced untoward sound reception. However, almost 90% reported positive experiences and the overall result for more than 80% was good. Operational difficulties resulted mainly from insufficient instruction. A moderate degree of instruction at the check-up was both essential and beneficial. Untoward sound experiences were caused mainly by inadequate venting and/or inaccurately adjusted instruments, faults that could be easily dealt with. It is therefore essential to teach local health service personnel that clients initially reporting problems in using their ITC can in most cases have their problems solved, mainly by simple instruction and/or an adjustment of the ITC. Only when these measures have failed should other types of hearing instruments (HI) be tried. Local health service personnel should therefore be instructed not to accept initial rejection of ITC merely because of the small size of the instrument until further instruction has been given, and not proved successful.

Audiologic Management of Bilateral External Auditory Canal Atresia With the Bone Conducting Implantable Hearing Device

The hearing impairment associated with congenital external auditory canal atresia has been managed with early bone conduction hearing aid placement and surgical reconstruction in selected patients. However, many patients do not wear a bone conduction hearing aid because of physical or social considerations and surgical reconstruction of the external auditory canal and middle ear may be difficult or contraindicated. This report details the use of implantable bone conducting hearing devices in five children with bilateral external auditory canal atresia. Each patient had bilateral conductive hearing impairment with normal bone conduction thresholds. Four of the five patients had associated craniofacial anomalies including three cases of microtia. The average preoperative sound field speech reception threshold improved from 63 dB to 13 dB with the implant. Patients experienced a definite preference for the implanted hearing device over the bone conduction hearing aid.

Arthropod bioacoustics: neurobiology and behaviour

Biophysics of sound and vibration mechanisms of sound production receptor mechanisms neuroethology of sound reception neuroethology of song production the functions of arthropod sound intraspecific acoustic communication - calling songs song in courtship and aggression acoustic communication in social arthropods genetics and evolution of song bioacoustic methods glossary of bioacoustic terms arthropod groups from which acoustic behaviour has been reported.

Sound generating outerwear and associated switches

A sound generating outer garment, such as a suit, a coat, or a jacket, includes switches and a sound generating circuit. The switches are connected to the sound generating circuit, and both the switches and the sound generating circuit are mounted in the garment. The sound generating circuit produces a sound or sounds in response to the actuation of one or more of the switches. Preferably, a switch is positioned at each shoulder and at each elbow of a coat or a jacket and at each knee of a pair of pants. The sound generating outer garment may also include a transmitter for transmitting the sound or sounds that are produced to an AM or FM receiver. Each switch may include a flexible and conductive first outer lamina and a flexible and insulating second outer lamina. Interposed between the two outer laminas is a resilient insulating cushion. The cushion has a number of holes formed through its thickness. Conductive projections are positioned on the second outer lamina in alignment with the holes formed in the cushion. These projections are electrically joined together so that if pressure is exerted anywhere on either outer lamina, one or more of the projections will contact the first outer lamina and complete the circuit through the switch. Mercury switches may also be employed in a sound generating outer garment.

Principle of sound reception with spatial separability.

Principle of sound reception with spatial separability.

Sound reception characteristics of a liquid state electromagnetic transducer

Sound reception characteristics of a liquid state electromagnetic transducer

Inverse filtering of room acoustics

A novel method is proposed for realizing exact inverse filtering of acoustic impulse responses in room. This method is based on the principle called the multiple-input/output inverse theorem (MINT). The inverse is constructed from multiple finite-impulse response (FIR) filters (transversal filters) by adding some extra acoustic signal-transmission channels produced by multiple loudspeakers or microphones. The coefficients of these FIR filters can be computed by the well-known rules of matrix algebra. Inverse filtering in a sound field is investigated experimentally. It is shown that the proposed method is greatly superior to previous methods that use only one acoustic signal-transmission channel. The results prove the possibility of sound reproduction and sound reception without any distortion caused by reflected sounds. >

Sound reception in two anabantid fishes

1. 1. Pure tone displacement sensitivity and bandwidth were measured from the saccule of the ear in two anabantid species ( Trichogaster trichopterus and Helostoma temincki) using microphonic potentials with a 1 μV RMS threshold for the second harmonic of the stimulus frequency. 2. 2. Saccular microphonics were recorded in both species from 80 to 1600 Hz, with lowest thresholds between 100 and 200 Hz. The overall microphonic response curves (sensitivity and bandwidth) of the two species were statistically similar to one another with an analysis of variance, although there were statistically different thresholds at 100 and 800 Hz. 3. 3. The hair cell orientation patterns of the saccular epithelia differ in the two species. Consequently, the comparative sizes of the saccular sensory epithelium and numbers of sensory hair cells were examined. The saccular sensory epithelium of Helostoma is about 40% larger and contains nearly 50% more hair cells than the saccular epithelium of a comparably sized Trichogaster. 4. 4. An extracranial air bubble, located in the suprabranchial chamber, is found in both species. The bubble has direct access to the saccular chamber in Trichogaster through a foramen which is absent in Helostoma. Despite the difference in morphology and the larger numbers of sensory hair cells in Helostoma, hearing sensitivity and bandwidth is similar in the two species. Although the structural differences in the auditory periphery do not affect pure tone sensitivity and bandwidth, other aspects of fish hearing such as frequency discrimination, discrimination of signals in the presence of noise, and/or sound localization ability may be affected by these structural differences.