The Effect of Depth and Content of the Middle Ear Cavity on Underwater Hearing Thresholds

1967 ◽  
Vol 42 (5) ◽  
pp. 1149-1149
Author(s):  
John F. Brandt
Keyword(s):  
Middle Ear ◽  
Hearing Thresholds ◽  
Underwater Hearing

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.

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.

Effect of Conductive Hearing Loss and Middle Ear Surgery on Binaural Hearing

1986 ◽  
Vol 95 (5) ◽  
pp. 525-530 ◽  
Author(s):  
Joseph W. Hall ◽  
Eugene L. Derlacki
Keyword(s):  
Hearing Loss ◽  
Middle Ear ◽  
Auditory Processing ◽  
Conductive Hearing Loss ◽  
Binaural Hearing ◽  
Middle Ear Surgery ◽  
Ear Surgery ◽  
Hearing Thresholds ◽  
Masking Level Difference ◽  
Conductive Hearing

This study investigated whether conductive hearing loss reduces normal binaural hearing advantages and whether binaural hearing advantages are normal in patients who have had hearing thresholds improved by middle ear surgery. Binaural hearing was assessed at a test frequency of 500 Hz using the masking level difference and interaural time discrimination thresholds. Results indicated that binaural hearing is often poor in conductive lesion patients and that the reduction in binaural hearing is not always consistent with a simple attenuation of the acoustic signal. Poor binaural hearing sometimes occurs even when middle ear surgery has resulted in bilaterally normal hearing thresholds. Our preliminary results are consistent with the interpretation that auditory deprivation due to conductive hearing loss may result in poor binaural auditory processing.

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