Biophysics of underwater hearing in anuran amphibians

1982 ◽  
Vol 98 (1) ◽  
pp. 49-66
Author(s):  
T. E. Hetherington ◽  
R. E. Lombard
Keyword(s):  
Middle Ear ◽  
Particle Motion ◽  
Sound Field ◽  
Underwater Sound ◽  
Resonant Frequencies ◽  
Hearing Sensitivity ◽  
Hearing Thresholds ◽  
Frog Species ◽  
Standing Wave Tube ◽  
Underwater Hearing

A standing wave tube apparatus was used to determine the biophysical basis of underwater hearing sensitivity in 3 species of Rana and in Xenopus laevis. A speaker inside the base of a vertical, water-filled 3 m steel pipe produced standing waves. Pressure and particle motion were measured with a hydrophone and geophone respectively and were spatially 90 degrees out of phase along the length of the tube. Microphonic responses were recorded from the inner ear of frogs lowered through pressure and particle motion maxima and minima. The air-filled lungs of whole frogs produced distortions of the sound field. Preparations of heads with only an air-filled middle ear produced little distortion and showed clear pressure tracking at sound intensities 10-20 dB above hearing thresholds from 200-3000 Hz. Filling the middle ear with water decreased or abolished microphonic responses. Severing the stapes reduced responses except at certain frequencies below about 1000 Hz which varied with body size and likely represent resonant frequencies of the middle ear cavity. We conclude that the frog species examined respond to underwater sound pressure from about 200-3000 Hz with the middle ear cavity responsible for pressure transduction.

Silent sounds in the Andes: underwater vocalizations of three frog species with reduced tympanic middle ears (Anura: Telmatobiidae: Telmatobius)

2017 ◽  
Vol 95 (5) ◽  
pp. 335-343 ◽  
Author(s):  
A.E. Brunetti ◽  
A. Muñoz Saravia ◽  
J.S. Barrionuevo ◽  
S. Reichle
Keyword(s):  
Tympanic Membrane ◽  
Prior Knowledge ◽  
Middle Ear ◽  
Related Species ◽  
Tympanic Cavity ◽  
The Andes ◽  
Ear Morphology ◽  
Frog Species ◽  
Underwater Hearing ◽  
Ear Reduction

Underwater vocalization in anurans is restricted to a few, distantly related species. In some of them, sound is transmitted through tympanic and extra-tympanic pathways. Members of the Andean genus Telmatobius Wiegmann, 1834 lack a tympanic membrane, and earlier reports assumed the absence of vocalizations in the genus. We recorded underwater vocalizations and examined the middle-ear morphology in three species of Telmatobius with different lifestyles: Telmatobius oxycephalus Vellard, 1946 (semiaquatic, riverine); Telmatobius hintoni Parker, 1940 (markedly aquatic, riverine); Telmatobius culeus (Garman 1876) (fully aquatic, lacustrine). Males emit underwater calls, which in the three species are simple and stereotyped; they consist of a repeated train of notes, with a low fundamental frequency (309–941 Hz). In each of the three species, the tympanic membrane is absent and the tympanic cavity is extremely reduced or absent, whereas the opercular system is well developed. Our data, along with prior knowledge in other species of anurans, suggest that the species examined here probably perceived sound through extra-tympanic pathways. Given the limited knowledge about underwater calling in anurans, Telmatobius seems a logical candidate to study the functional and evolutionary bases of underwater hearing and tympanic middle-ear reduction in anurans.

In-air and underwater hearing sensitivity of a northern elephant seal (Mirounga angustirostris)

1999 ◽  
Vol 77 (11) ◽  
pp. 1751-1758 ◽  
Author(s):  
D Kastak ◽  
R J Schusterman
Keyword(s):  
Sound Intensity ◽  
Elephant Seal ◽  
Mirounga Angustirostris ◽  
Underwater Sound ◽  
Northern Elephant Seal ◽  
Low Frequencies ◽  
Hearing Sensitivity ◽  
Deep Diving ◽  
Sound Detection ◽  
Underwater Hearing

In-air and underwater sound detection thresholds were obtained for a female northern elephant seal (Mirounga angustirostris). Hearing sensitivity in air was generally poor, but was best for frequencies between 3.2 and 15 kHz, and showed greatest sensitivity at 6.3 kHz (43 dB re: 20 µPa). The upper frequency limit in air was approximately 20 kHz. The underwater audiogram is similar to those obtained from other phocids in that sensitivity was best between 3.2 and 45 kHz, with greatest sensitivity at 6.4 kHz (58 dB re: 1 µPa) and an upper frequency cutoff of approximately 55 kHz. The elephant seal was more sensitive to low frequencies (<1 kHz) than other pinnipeds tested. Thresholds obtained in water were lower than those obtained in air (19 dB in terms of sound pressure, 52 dB in terms of sound intensity), indicating that the elephant seal is adapted for underwater hearing. The outer and middle ears of the elephant seal are modified relative to those of other phocids. These modifications are probably needed to cope with extreme static pressures related to deep diving, and are likely to confer relatively good auditory sensitivity under water.

scholarly journals Specialization for underwater hearing by the tympanic middle ear of the turtle, Trachemys scripta elegans

2012 ◽  
Vol 279 (1739) ◽  
pp. 2816-2824 ◽  
Author(s):  
Jakob Christensen-Dalsgaard ◽  
Christian Brandt ◽  
Katie L. Willis ◽  
Christian Bech Christensen ◽  
Darlene Ketten ◽  
...  
Keyword(s):  
Middle Ear ◽  
Sound Intensity ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Underwater Sound ◽  
Laser Vibrometry ◽  
Surrounding Water ◽  
Before And After ◽  
Brainstem Response ◽  
Underwater Hearing

Turtles, like other amphibious animals, face a trade-off between terrestrial and aquatic hearing. We used laser vibrometry and auditory brainstem responses to measure their sensitivity to vibration stimuli and to airborne versus underwater sound. Turtles are most sensitive to sound underwater, and their sensitivity depends on the large middle ear, which has a compliant tympanic disc attached to the columella. Behind the disc, the middle ear is a large air-filled cavity with a volume of approximately 0.5 ml and a resonance frequency of approximately 500 Hz underwater. Laser vibrometry measurements underwater showed peak vibrations at 500–600 Hz with a maximum of 300 µm s −1 Pa −1 , approximately 100 times more than the surrounding water. In air, the auditory brainstem response audiogram showed a best sensitivity to sound of 300–500 Hz. Audiograms before and after removing the skin covering reveal that the cartilaginous tympanic disc shows unchanged sensitivity, indicating that the tympanic disc, and not the overlying skin, is the key sound receiver. If air and water thresholds are compared in terms of sound intensity, thresholds in water are approximately 20–30 dB lower than in air. Therefore, this tympanic ear is specialized for underwater hearing, most probably because sound-induced pulsations of the air in the middle ear cavity drive the tympanic disc.

scholarly journals Spiral Sound Wave Transducer Based on the Longitudinal Vibration

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3674 ◽  
Author(s):  
Wei Lu ◽  
Yu Lan ◽  
Rongzhen Guo ◽  
Qicheng Zhang ◽  
Shichang Li ◽  
...  
Keyword(s):  
Sound Wave ◽  
Longitudinal Vibration ◽  
Three Dimensional ◽  
Low Frequency ◽  
Sound Field ◽  
Field Measurements ◽  
Sound Waves ◽  
Underwater Sound ◽  
Three Dimensional Finite Element ◽  
Wave Transducer

A spiral sound wave transducer comprised of longitudinal vibrating elements has been proposed. This transducer was made from eight uniform radial distributed longitudinal vibrating elements, which could effectively generate low frequency underwater acoustic spiral waves. We discuss the production theory of spiral sound waves, which could be synthesized by two orthogonal acoustic dipoles with a phase difference of 90 degrees. The excitation voltage distribution of the transducer for emitting a spiral sound wave and the measurement method for the transducer is given. Three-dimensional finite element modeling (FEM)of the transducer was established for simulating the vibration modes and the acoustic characteristics of the transducers. Further, we fabricated a spiral sound wave transducer based on our design and simulations. It was found that the resonance frequency of the transducer was 10.8 kHz and that the transmitting voltage resonance was 140.5 dB. The underwater sound field measurements demonstrate that our designed transducer based on the longitudinal elements could successfully generate spiral sound waves.

scholarly journals Self-reported hearing status and audiometric thresholds among college students using headphones

2021 ◽  
Vol 13 (3) ◽  
pp. 60-68
Author(s):  
Yash Shrimal ◽  
Aparna Nandurkar
Keyword(s):  
Management Strategies ◽  
Self Report ◽  
Convenience Sample ◽  
Hearing Sensitivity ◽  
Hearing Status ◽  
College Going ◽  
Hearing Thresholds ◽  
Hearing Difficulty ◽  
Listening Habits ◽  
Insert Earphones

Purpose: The study aims to investigate headphone listening habits of college-going students and for those using headphones, correlate self-reported hearing status with average audiometric hearing thresholds. Method: Headphone listening habits and awareness of adverse effects of the same was profiled in college-going students using a questionnaire distributed through online platform. Hearing thresholds were then compared for those with and without self-report of hearing difficulty. 341 responses were obtained from students between 17 and 23 years of age. For the second part of the study, a convenience sample of 30 willing students from among these 341 was selected. Pure tone thresholds were obtained for various frequencies with a high frequency audiometer. PTA (average of 500, 1000, 2000 Hz) and HFPTA (average of 4000, 6000, 8000, 10000 Hz) were calculated for both the ears and compared for those with and without reported hearing difficulty. Results: 78% students reported headphone usage for less than 3 hours per day, while 22% reported usage for more than 3 hours per day. 77% respondents were aware that listening to loud sounds can alter hearing sensitivity, but many (54.83%) did not have awareness about the minimum safe hours of listening. There was a weak positive correlation between self-reported hearing difficulty and poor ear HFPTA (r = 0.2304). Conclusion: Majority of students used insert earphones even after knowing the adverse effect of the same. There was a weak correlation found between the self-reported hearing problems and audiometric hearing thresholds. Implication: More awareness is needed about the ill effects of headphone usage amongst the young teenage population. Proper counseling and management strategies are required for people who report difficulty in hearing.

scholarly journals Parametric spatial post-filtering utilising high-order circular harmonics with applications to underwater sound-field visualisation

2021 ◽  
Vol 149 (6) ◽  
pp. 4463-4476
Author(s):  
Vasileios Bountourakis ◽  
Leo McCormack ◽  
Mathias Winberg ◽  
Ville Pulkki
Keyword(s):  
Sound Field ◽  
High Order ◽  
Underwater Sound
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