scholarly journals Establishing critical differences in ear-canal stimulus amplitude for detecting middle ear muscle reflex activation during olivocochlear efferent measurements

2019 ◽  
Vol 59 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Ian B. Mertes
1982 ◽  
Vol 93 (sup386) ◽  
pp. 100-102 ◽  
Author(s):  
J. Luotonen ◽  
A. M. M. Jokipii ◽  
P. Sipilä ◽  
J. Väyrynen ◽  
L. Jokipii ◽  
...  

1993 ◽  
Vol 36 (1) ◽  
pp. 178-185 ◽  
Author(s):  
Janet E. Shanks ◽  
Richard H. Wilson ◽  
Nancy K. Cambron

Three methods for compensating multiple frequency acoustic admittance measurements for ear canal volume were studied in 26 men with normal middle ear transmission systems. Peak compensated static acoustic admittance (| y |) and phase angle (ø) were calculated from sweep frequency tympanograms (226–1243 Hz in 113 Hz increments). Of the procedures used to compensate for volume in rectangular form, the ear canal pressure used to estimate volume had the largest effect on the estimate of middle ear resonance. Median resonance was 800 Hz for admittance measurements compensated at 200 daPa versus 1100 Hz for measurements compensated at –350 daPa. The remaining two methods, compensation of susceptance only versus both susceptance and conductance and compensation using the minimum volume versus separate volumes at each frequency, did not affect estimates of middle ear resonance. Estimates of middle ear resonance from compensated phase angle measurements also were compared with estimates of resonance from admittance and phase difference curves. although resonance could not be estimated from the phase difference curve, resonance estimated from the admittance difference curve agreed with the estimate from compensated phase angle.


Author(s):  
Marcus Brown ◽  
John Bradshaw ◽  
Rong Z. Gan

Abstract Blast-induced injuries affect the health of veterans, in which the auditory system is often damaged, and blast-induced auditory damage to the cochlea is difficult to quantify. A recent study modeled blast overpressure (BOP) transmission throughout the ear utilizing a straight, two-chambered cochlea, but the spiral cochlea's response to blast exposure has yet to be investigated. In this study, we utilized a human ear finite element (FE) model with a spiraled, two-chambered cochlea to simulate the response of the anatomical structural cochlea to BOP exposure. The FE model included an ear canal, middle ear, and two and half turns of two-chambered cochlea and simulated a BOP from the ear canal entrance to the spiral cochlea in a transient analysis utilizing fluid-structure interfaces. The model's middle ear was validated with experimental pressure measurements from the outer and middle ear of human temporal bones. The results showed high stapes footplate displacements up to 28.5µm resulting in high intracochlear pressures and basilar membrane (BM) displacements up to 43.2µm from a BOP input of 30.7kPa. The cochlea's spiral shape caused asymmetric pressure distributions as high as 4kPa across the cochlea's width and higher BM transverse motion than that observed in a similar straight cochlea model. The developed spiral cochlea model provides an advancement from the straight cochlea model to increase the understanding of cochlear mechanics during blast and progresses towards a model able to predict potential hearing loss after blast.


2015 ◽  
Vol 35 (6) ◽  
pp. 583-589 ◽  
Author(s):  
Leandro L. Martins ◽  
Ijanete Almeida-Silva ◽  
Maria Rossato ◽  
Adriana A.B. Murashima ◽  
Miguel A. Hyppolito ◽  
...  

Abstract: Paca (Cuniculus paca), one of the largest rodents of the Brazilian fauna, has inherent characteristics of its species which can conribute as a new option for animal experimantation. As there is a growing demand for suitable experimental models in audiologic and otologic surgical research, the gross anatomy and ultrastructural ear of this rodent have been analyzed and described in detail. Fifteen adult pacas from the Wild Animals Sector herd of Faculdade de Ciências Agrárias e Veterinárias, Unesp-Jaboticabal, were used in this study. After anesthesia and euthanasia, we evaluated the entire composition of the external ear, registering and ddescribing the details; the temporal region was often dissected for a better view and detailing of the tympanic bulla which was removed and opened to expose the ear structures analyzed mascroscopically and ultrastructurally. The ear pinna has a triangular and concave shape with irregular ridges and sharp apex. The external auditory canal is winding in its path to the tympanic mebrane. The tympanic bulla is is on the back-bottom of the skull. The middle ear is formed by a cavity region filled with bone and membranous structures bounded by the tympanic membrane and the oval and round windows. The tympanic membrane is flat and seals the ear canal. The anatomy of the paca ear is similar to the guinea pig and from the viewpoint of experimental model has major advantages compared with the mouse ear.


1994 ◽  
Vol 73 (1) ◽  
pp. 47-48
Author(s):  
Alper Tutkun ◽  
Caglar Batman ◽  
Cüneyt Üneri ◽  
Mehmet Ali Sehitoglu

This study has been performed between December 1990—March 1991 in the Microsurgery laboratory of the Marmara University Hospital. Twelve healthy albino guinea pigs were used as a study group while the control group consists of three animals. The potentials for cholesteatoma formation of the squamous epithelium, namely the squamous epithelium of the posterior superior part of the external ear canal skin and normal skin, were investigated. Among 24 subjects who were implanted by canal skin, cholesteatoma was fanned in 21 of them. Likewise, 19 of 24 animals implanted by normal skin came out with cholesteatoma formation. Between these two types of epithelium, there is no statistical difference in cholesteatoma formation (p >0.5).


2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Takumi Hawa ◽  
Rong Z. Gan

High intensity noise/impulse transmission through a bench model consisting of the simplified ear canal, eardrum, and middle ear cavity was investigated using the CFX/ANSYS software package with fluid-structure interactions. The nondimensional fluid-structure interaction parameter q and the dimensionless impulse were used to describe the interactions between the high intensity pressure impulse and eardrum or tympanic membrane (TM). We found that the pressure impulse was transmitted through the straight ear canal to the TM, and the reflected overpressure at the TM became slightly higher than double the incident pressure due to the dynamic pressure (shocks) effect. Deformation of the TM transmits the incident pressure impulse to the middle ear cavity. The pressure peak in the middle ear cavity is lower than the incident pressure. This pressure reduction through the TM was also observed in our experiments that have dimensions similar to the simulation bench model. We also found that the increase of the pressure ratio as a function of the incident pressure is slightly larger than the linear growth rate. The growth rate of the pressure ratio in this preliminary study suggests that the pressure increase in the middle ear cavity may become sufficiently high to induce auditory damage and injury depending on the intensity of the incident sound noise.


1994 ◽  
Vol 108 (7) ◽  
pp. 607-609 ◽  
Author(s):  
Abduljabbar Alshaikhly ◽  
Abdalla M. Hamid ◽  
Bahram Azadeh

AbstractA 64-year-old Qatari female, with a one-year history of right otorrhoea and deafness, had a reddish-white mass projecting into the right ear canal, through the tympanic membrane, that proved histopathologically to be a paraganglioma. Computerized tomography (CT) of the temporal bones showed extensive destruction of the right mastoid bone, the posterior ear canal wall, and the sinus plate, with total disruption of the ossicles, simulating a malignant tumour, which is unusual for a middle ear paraganglioma.


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