scholarly journals Differential Effects on Underwater Hearing Thresholds of Air and Water Interface with the Tympanic Membrane

1967 ◽  
Vol 42 (5) ◽  
pp. 1192-1193
Author(s):  
Harry Hollien
Keyword(s):  
Tympanic Membrane ◽  
Water Interface ◽  
Differential Effects ◽  
Hearing Thresholds ◽  
Underwater Hearing

Tympanic membrane atelectasis in childhood otitis media with effusion

1995 ◽  
Vol 109 (6) ◽  
pp. 495-498 ◽  
Author(s):  
H. L. Tay ◽  
R. P. Mills
Keyword(s):  
Multivariate Analysis ◽  
Tympanic Membrane ◽  
Otitis Media With Effusion ◽  
Pars Tensa ◽  
Hearing Thresholds ◽  
Inferior Segment ◽  
Glue Ear ◽  
The Difference ◽  
A Prospective Study ◽  
Relevant Factors

AbstractA prospective study on the dynamics of tympanic membrane atelectasis during the treatment for glue ear was performed in a sample of 115 ears of 83 children aged between one and 11 years. The progression in the degree of pars tensa atelectasis was analysed in relation to six potentially relevant factors. Multivariate analysis showed that the factor with the most predictive value on the progression of the pars tensa retraction was the grade of atelectasis at initial detection (p<0.0001). The use of grommets did not have any significant influence on the outcome grade of atelectasis. There was an association between previous grommet insertion and localized retractions in the inferior segment of the pars tensa (P<0.0001). However, localized retractions in the postero-superior quadrant were not associated with previous grommet insertion (P<0.02). Although the hearing thresholds of atelectatic ears were significantly worse than normal ears especially at 4 kHz (p<0.006), the difference was less than 5 dB.

Underwater Hearing in the Frog, Rana Catesbeiana

1981 ◽  
Vol 91 (1) ◽  
pp. 57-71 ◽  
Author(s):  
R. ERIC LOMBARD ◽  
RICHARD R. FAY ◽  
YEHUDAH L. WERNER
Keyword(s):  
Sound Pressure ◽  
Rana Catesbeiana ◽  
Sound Intensity ◽  
Torus Semicircularis ◽  
Intensity Level ◽  
Hearing Thresholds ◽  
Average Loss ◽  
Two Measures ◽  
Underwater Hearing ◽  
Hearing Abilities

Comparable auditory sound pressure level (SPL) and sound intensity level(SIL) threshold curves were determined in air and under water in Ranacatesbeiana. Threshold curves were determined using chronic metal electrodeimplants which detected multi-unit responses of the torus semicircularis toincident sound. In terms of SPL, hearing thresholds in water and air aresimilar below 0.2 kHz. Above 0.2 kHz, the sensitivity under water falls of fat about 16 dB/octave to reach an average loss of about 30 dB above 0.4 kHz. In terms of SIL, the organism is about 30 dB more sensitive under water than in air below 0.2 kHz and equally sensitive in air and water above 0.4 kHz.The relative merits of the two measures are discussed and an attempt is made to relate the results to morphology of the middle and inner ears. This report is the first to compare aerial and underwater hearing abilities in any organism using electrode implants.

Effects of a neoprene wetsuit hood on low‐frequency underwater hearing thresholds

1999 ◽  
Vol 105 (2) ◽  
pp. 1298-1298 ◽  
Author(s):  
John R. Sims ◽  
David M. Fothergill ◽  
Michael D. Curley
Keyword(s):  
Low Frequency ◽  
Hearing Thresholds ◽  
Underwater Hearing

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.

scholarly journals Underwater Hearing Thresholds

1967 ◽  
Vol 41 (6) ◽  
pp. 1603-1603
Author(s):  
John F. Brandt ◽  
Harry Hollien ◽  
Carl Thompson
Keyword(s):  
Hearing Thresholds ◽  
Underwater Hearing

scholarly journals Dual sound reception apparatus in protocetid whales

2021 ◽  
Author(s):  
Mickaël Joël Mourlam
Keyword(s):  
Tympanic Membrane ◽  
Aquatic Environment ◽  
Lateral Wall ◽  
Transmission Mechanism ◽  
Bone Thickness ◽  
Sound Reception ◽  
Auditory Region ◽  
Acoustic Conditions ◽  
Underwater Hearing ◽  
Hearing System

Modern cetaceans dwell in an underwater world of sound. Due to the specific physico-acoustic conditions inherent in the aquatic environment, sound reception pathway in modern whales drastically differs from that of land mammals and implies deep modification of their external acoustic apparatus. To fathom the implementation of this underwater hearing system, the rare data on the auditory region of early whales are paramount. Among them, previous studies on protocetid auditory region highlighted the presence of two potential acoustic portals on the lateral wall of the bulla: a tympanic ring and a tympanic plate. Through an anatomical survey, I explore the external sound reception apparatus of a protocetid whale and discuss the functionality of these two sound portals. The study of the tympanic ring, allow me to propose a reconstruction of the tympanic membrane of this early whale, suggesting that this structure was functional for aerial hearing. 3D investigation of the bone thickness of the bulla reveals the presence of homologous areas of reduced thickness within the tympanic plate of protocetid and modern cetaceans, highlighting a common functioning of this structure for underwater hearing. Thus, this detailed anatomical survey of the lateral wall of a protocetid tympanic bulla confirms the functionality of the two contiguous acoustic portals and sheds new light on the sound transmission mechanism in these early whales.

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.

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