Effect of Air Bubbles in the External Auditory Meatus on Underwater Hearing Thresholds

1969 ◽  
Vol 46 (2B) ◽  
pp. 384-387 ◽  
Author(s):  
Harry Hollien ◽  
John F. Brandi
Keyword(s):  
External Auditory Meatus ◽  
Air Bubbles ◽  
Hearing Thresholds ◽  
Underwater Hearing

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

scholarly journals Misdiagnosis of hearing loss due to ear canal collapse: a report of two cases

1996 ◽  
Vol 110 (6) ◽  
pp. 561-566 ◽  
Author(s):  
Cliodna F. O Mahoney ◽  
Linda M. Luxon
Keyword(s):  
Hearing Loss ◽  
External Auditory Meatus ◽  
Noise Induced Hearing Loss ◽  
Ear Canal ◽  
True Nature ◽  
High Frequencies ◽  
Hearing Thresholds ◽  
Retrocochlear Pathology

AbstractCollapse of the external auditory meatus during audiometry can lead to spuriously increased hearing thresholds being obtained, particularly at high frequencies, and may simulate conditions such as noise-induced hearing loss, presbyacusis and retrocochlear pathology. Consequently, inappropriate investigations and management may be undertaken. Two patients with elevated thresholds secondary to ear canal collapse are described. The implications of initially failing to identify the true nature of their ‘hearing losses’ are highlighted and strategies to avoid such pitfalls are discussed.

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

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.

Detection thresholds of a harbour seal to repeated underwater high-frequency, short-duration sinusoidal pulses

1988 ◽  
Vol 66 (7) ◽  
pp. 1578-1582 ◽  
Author(s):  
J. M. Terhune
Keyword(s):  
High Frequency ◽  
Threshold Energy ◽  
Phoca Vitulina ◽  
Harbour Seal ◽  
Specific Time ◽  
Detection Thresholds ◽  
Time Period ◽  
Hearing Thresholds ◽  
Number Of Cycles ◽  
Underwater Hearing

Underwater hearing thresholds of a harbour seal (Phoca vitulina) were obtained from 1 to 64 kHz using sinusoidal pulses as short as 0.5 ms. The lowest threshold was 57 dB (re 1 μPa) at 8 kHz. Thresholds for 500- to 50-ms tones increased to about 70 dB (re 1 μPa) in the 1- to 4-kHz and 32-kHz ranges and to 111 dB (re 1 μPa) at 64 kHz. At 50 ms duration, thresholds were from 0 to 6 dB greater than the maximum sensitivity for each frequency tested. Thus, only very brief seal vocalizations are not as audible as longer (and equally loud) underwater calls. For pulses shorter than 400 cycles, the thresholds increased linearly with the logarithm of the number of cycles, independent of frequency (4–32 kHz). The total energy of the pulses at threshold was estimated. From 4 to 32 kHz, as the pulse durations shortened, the threshold energy value decreased and then began to increase. These findings bring into question the concept that when presented with high-frequency sound, the auditory system integrates energy for a specific time period.

Reliability of underwater hearing thresholds in pinnipeds

2005 ◽  
Vol 6 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Brandon L. Southall ◽  
Ronald J. Schusterman ◽  
David Kastak ◽  
Colleen Reichmuth Kastak
Keyword(s):  
Hearing Thresholds ◽  
Underwater Hearing
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