Effects of External Ear Canal Pressure on the Middle-Ear Muscle Reflex Threshold

1974 ◽  
Vol 17 (3) ◽  
pp. 526-530 ◽  
Author(s):  
Frederick N. Martin ◽  
Sherry Coombes
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
External Auditory Canal ◽  
Acoustic Impedance ◽  
Normal Hearing ◽  
Air Pressure ◽  
External Ear ◽  
Ear Canal ◽  
Acoustic Reflex ◽  
Reflex Threshold

Twenty normal-hearing individuals served as subjects in an experiment designed to determine the relationships between positive and negative air pressure in the external auditory canal and the intensity required to elicit the acoustic reflex. Pressure was varied from +240 to −240 mm H 2 O. Changes in the magnitude of acoustic impedance were measured on an acoustic impedance meter and displayed graphically on a Y-T recorder. As air pressure was varied in the canal and the tympanic membrane was displaced from its position of greatest compliance, systematic increases in the intensity required to elicit the reflexes were noted. The magnitude of the differences was smaller than might have been anticipated, not exceeding a mean of 5.1 dB at −240 mm H 2 O.

scholarly journals Macroscopic description of the external and middle ear of paca (Cuniculus paca Linnaeus, 1766)

2015 ◽  
Vol 35 (6) ◽  
pp. 583-589 ◽  
Author(s):  
Leandro L. Martins ◽  
Ijanete Almeida-Silva ◽  
Maria Rossato ◽  
Adriana A.B. Murashima ◽  
Miguel A. Hyppolito ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Gross Anatomy ◽  
Experimental Models ◽  
Temporal Region ◽  
External Ear ◽  
Wild Animals ◽  
Ear Canal ◽  
Macroscopic Description ◽  
Mouse Ear

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.

scholarly journals External ear canal cholesteatoma after ventilation tube insertion and mastoidectomy

2012 ◽  
Vol 69 (4) ◽  
pp. 363-366 ◽  
Author(s):  
Dragoslava Djeric ◽  
Milan Jovanovic ◽  
Ivan Baljosevic ◽  
Srbislav Blazic ◽  
Milanko Milojevic
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Membrane Surface ◽  
Tube Placement ◽  
External Ear ◽  
Ventilation Tube ◽  
Ear Canal ◽  
Tube Insertion ◽  
Tissue Mass ◽  
External Ear Canal

Introduction. Etiopathogenetically, there are two types of chollesteatomas: congenital, and acquired. Numerous theories in the literature try to explain the nature of the disease, however, the question about cholesteatomas remain still unanswered. The aim of the study was to present a case of external ear canal cholesteatoma (EEC) developed following microsurgery (ventilation tube insertion and mastoidectomy), as well as to point ant possible mechanisms if its development. Case report. A 16-yearold boy presented a 4-month sense of fullness in the ear and otalgia on the left side. A year before, mastoidectomy and posterior atticotomy were performed with ventilation tube placement due to acute purulent mastoiditis. Diagnosis was based on otoscopy examination, audiology and computed tomography (CT) findings. CT showed an obliterative soft-tissue mass completely filled the external ear canal with associated erosion of subjacent the bone. There were squamous epithelial links between the canal cholesteatoma and lateral tympanic membrane surface. They originated from the margins of tympanic membrane incision made for a ventilation tube (VT) insertion. The position of VT was good as well as the aeration of the middle ear cavity. The tympanic membrane was intact and of normal appearance without middle ear extension or mastoid involvement of cholesteatoma. Cholesteatoma and ventilation tube were both removed. The patient recovered without complications and shortly audiology revealed hearing improving. Follow-up 2 years later, however, showed no signs of the disease. Conclusion. There could be more than one potential delicate mechanism of developing EEC in the ear with VT insertion and mastoidectomy. It is necessary to perform routine otologic surveillance in all patients with tubes. Affected ear CT scan is very helpful in showing the extent of cholesteatoma and bony defects, which could not be assessed by otoscopic examination alone.

Expression of Cytokeratins 13 and 16 in Middle Ear Cholesteatoma

1994 ◽  
Vol 110 (3) ◽  
pp. 310-317 ◽  
Author(s):  
Hiroyuki Sasaki ◽  
Cheng-Chun Huang
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Basal Layer ◽  
External Ear ◽  
Ear Canal ◽  
Suprabasal Layer ◽  
External Ear Canal ◽  
Cytokeratin Expression ◽  
Middle Ear Cholesteatoma ◽  
Cytokeratin 13

The accumulation of keratinizing epithelium in the middle ear cavity is a crucial factor in the pathogenesis of cholesteatoma. We hypothesize that keratinocytes from the skin of the ear canal migrate and hyperprollferate in response to Inflammation in the middle ear cavity to cause accumulation of keratin debris. In the present study, we Investigated the expression of specific cytokeratins (CKs) in the cholesteatoma matrix to determine whether cholesteatoma is a hyperproliferative disease. Cytokeratin expression was examined in cholesteatoma, meatal skin, and tympanic membrane with two monoclonal antibodies, one for both cytokeratins 13 and 16 (antibody K8.12), and another for cytokeratin 13 only (antibody K5–1A3). CK 13 (MW 51 KD) Is a marker of differentiation and CK 16 (MW 48 KD) is a marker of hyperproliferatlon of keratinocytes. The use of immunoblot probes showed that CKs 13 and 16 were present in cholesteatoma. Immunofluorescenf staining showed the presence of CK 16 In the suprabasal layer of cholesteatoma, which was located near the external ear canal. CK 16 was also localized in the suprabasal layer of meatal skin and tympanic membrane. CK 13 was localized in the basal layer of the cholesteatoma, distal to the external ear canal, but not in the meatal skin and tympanic membrane. Taken together, the present data suggest that cholesteatoma is a hyperprollferative disease and that cholesteatoma expresses CK 16 near the external ear canal and transforms to express CK 13 during growth distally.

Factors Influencing the Acoustic-Immittance Characteristics of the Acoustic Reflex

1979 ◽  
Vol 22 (3) ◽  
pp. 480-499 ◽  
Author(s):  
Richard H. Wilson
Keyword(s):  
Middle Ear ◽  
Sound Pressure ◽  
Broadband Noise ◽  
Intensity Level ◽  
Ear Canal ◽  
Acoustic Reflex ◽  
Impedance Characteristics ◽  
Reflex Threshold ◽  
Acoustic Reflex Threshold ◽  
Tonal Stimuli

Measurements of the aural acoustic-immittance (admittance and impedance) characteristics of the middle-ear transmission system in humans during the quiescent (static) and reflexive states were made (N = 36) utilizing a signal-averaging technique. Three pure tones (750, 1000, and 2000 Hz) and broadband noise stimuli elicited the acoustic reflex in 2-dB steps at sound-pressure levels from 84–116 dB (tones) and 66–116 dB (noise) during ascending- and descending-intensity level runs. The contralateral middle-ear activity was monitored with a 220-Hz probe by digitizing the conductance and susceptance outputs of an admittance meter. A computer corrected for the ear-canal volume utilizing measurements made at ear-canal pressures of 0 and −350 daPa and then converted the conductance and susceptance values into admittance and impedance units. The results were reported in absolute and relative immittance units, including components, as a function of both stimulus sound-pressure level and intensity level above the acoustic-reflex threshold. The static immittance of the middle ear changed nonlinearly over time to lower admittance or higher impedance values. The influence of this static-immittance shift on the reflex magnitude was discussed. The largest mean reflex magnitude and the slowest rate of growth were observed with broadband noise, although eight of the 36 subjects demonstrated the largest reflex magnitude in response to one or more of the tonal stimuli. Although static-immittance values and acoustic-reflex thresholds were poorly correlated, the reflex magnitudes were proportional to static immittance. The variability of the reflex measures was similar to the variability of the static-immittance values. Finally, bi-directional changes in resistance during the reflexive state were observed and discussed.

Tympanometric Detection of Middle Ear Effusion in Infants and Young Children

PEDIATRICS ◽  
1976 ◽  
Vol 58 (2) ◽  
pp. 198-210
Author(s):  
Jack L. Paradise ◽  
Clyde G. Smith ◽  
Charles D. Bluestone
Keyword(s):  
Young Children ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
External Auditory Canal ◽  
Air Pressure ◽  
Objective Test ◽  
Middle Ear Effusion ◽  
Highly Correlated ◽  
Ear Effusion ◽  
Infants And Young Children

Tympanometry, a test of middle ear status new to clinical pediatrics, was carried out on 280 subjects, 10 days through 5 years of age. The tympanograms obtained were compared with otoscopic findings and, in 107 of the subjects, with findings at myringotomy. Seven distinct tympanometric curve types were identified and defined, based on their degree of correlation with the presence or absence of middle ear effusion. In subjects 7 months of age and older, curves suggesting normal (high) tympanic membrane compliance in combination with atmospheric or near-atmospheric middle ear air pressure were rarely associated with effusion. Conversely, curves suggesting low tympanic membrane compliance were highly correlated with the presence of effusion. Curves suggesting intermediate compliance or reduced middle ear air pressure were also correlated with effusion, but the degree of correlation was dependent on the shape of the curve. In infants less than 7 months of age, many of the ears with effusion had "normal" tympanograms, presumably because external auditory canal walls in such infants tend to be highly distensible. Tympanometry is a simple, rapid, atraumatic, valid, and objective test, easily administered by paraprofessional personnel. Its use can result in improved detection of middle ear effusion and other middle ear abnormalities, and also appears to promote improvement in diagnostic acumen.

Does occurrence of keratinizing stratified squamous epithelium in the middle-ear cavity always indicate a cholesteatoma?

2004 ◽  
Vol 118 (10) ◽  
pp. 757-763 ◽  
Author(s):  
Lars-Eric Stenfors
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Squamous Epithelium ◽  
External Ear ◽  
Defence Mechanism ◽  
Ear Canal ◽  
Non Invasive ◽  
Tympanic Membrane Perforations ◽  
Acquired Cholesteatoma ◽  
Stratified Squamous Epithelium

The origin and behaviour of keratinizing stratified squamous epithelium, anessential component of cholesteatoma occurring in the middle-ear cavity, has puzzled otologistsfor decades. In this experimental study in 16 cats, central (n = 23) and peripheral (n = 9) tympanic membrane perforations were observed for up to 63 days before sacrifice. The tympanic membranes with bony rim were excised, decalcified and embedded in Epon 812. Sections werestained with toluidine blue and examined using a light microscope. The perforation had been sealed by meatal epithelium exhibiting pronounced hyperplasia and keratin formation, lying on abedof granulation tissue. Subtotal central perforations healed within 14 days, forming a bowl-shaped tympanic membrane and leaving parts of the handle of the malleus (with meatal epithelium) protruding freely into the middle-ear cavity. Stratified squamous epithelium, morphologicallyidentical with that of external ear canal epidermis, could be observed on the malleus even 63 days after operation. This meatal epithelium was non-keratinizing, non-invasive, and showed no destructive properties typical of acquired cholesteatoma. During certain circumstances, the cellcycle of hyperplastic epidermal epithelium within the middle-ear cavity can evidently be arrested and inactivated by a local defence mechanism.

Acoustic-Reflex Dynamics for Pulsed Signals

1978 ◽  
Vol 21 (2) ◽  
pp. 295-308
Author(s):  
Terry L. Wiley ◽  
Raymond S. Karlovich
Keyword(s):  
Duty Cycle ◽  
Acoustic Impedance ◽  
Normal Hearing ◽  
Broadband Noise ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Acoustic Reflex ◽  
Stapedius Muscle ◽  
Duty Cycles

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.

Prevalence of external auditory canal exostoses in Australian surfboard riders

2004 ◽  
Vol 118 (5) ◽  
pp. 348-351 ◽  
Author(s):  
William Hurst ◽  
Michael Bailey ◽  
Benjamin Hurst
Keyword(s):  
External Auditory Canal ◽  
Cold Water ◽  
Control Group ◽  
External Ear ◽  
Ear Canal ◽  
External Ear Canal ◽  
Rate Of Growth

This paper assessed 300 surfboard riders, comprising 229 males and 71 females to determine the prevalence and rate of growth of exostoses in this population. A group of cold water swimmers and a control group were also examined. Significant obstruction, defined as two thirds or more occlusion of the ear canal was noted in 90 of the male surfers and 10 female surfers. This degree of occlusion was found in seven of the 32 cold water swimmers. A male surfer who has surfed regularly for 20 years or more has a one in two chance of developing significant obstruction of the external ear canal resulting from exostoses and this is a three in seven chance for females.

The Prediction of Hearing Loss in Persons With Cerebral Palsy Using Contralateral Acoustic Reflex Threshold for Broad-Band Noise

2003 ◽  
Vol 12 (2) ◽  
pp. 91-95
Author(s):  
Michele B. Emmer ◽  
Shlomo Silman
Keyword(s):  
Hearing Loss ◽  
Cerebral Palsy ◽  
Broad Band ◽  
Screening Method ◽  
Accurate Method ◽  
Normal Hearing ◽  
Acoustic Reflex ◽  
Band Noise ◽  
Reflex Threshold ◽  
Acoustic Reflex Threshold

The utility of R. Keith’s (1977) method of screening for hearing sensitivity using the contralateral acoustic-reflex threshold (ART) for broad-band noise (BBN) was tested in persons with cerebral palsy (CP). Three groups of participants were included in this prospective study. The first group comprised 20 normal-hearing individuals without CP whose results were used as normative data. The second group comprised 16 participants with normal hearing and CP. The third group comprised 22 participants with sensorineural hearing loss and CP. The results of this study indicate that Keith’s screening method employing ART for BBN can be used successfully in a population with multiple handicaps where a quick, inexpensive, readily available, and accurate method is needed.

scholarly journals Late Presentation of Idiopathic Tympanic Membrane Ossification with External Auditory Canal Stenosis

2015 ◽  
Vol 7 (3) ◽  
pp. 141-143
Author(s):  
Hitesh Verma
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
External Auditory Canal ◽  
Special Form ◽  
Rare Case ◽  
Late Presentation ◽  
Canal Stenosis ◽  
Middle Ear Cleft

ABSTRACT The external auditory canal (EAC) is formed by lateral cartilaginous and medial bony part. The stenosis of EAC is narrowing of the width of the EAC, i.e. either caused by congenital or acquired causes. Myringosclerosis is a condition caused by calcification of tissues in the tympanic membrane and ossification is a special form of fibrosis due to the long-term, irreversible continued inflammation in the middle ear cleft. We are presenting rare case of idiopathic tympanic membrane ossification with generalized stenosis of EAC in 29-year-old patient. How to cite this article Verma H, Dass A, Singhal SK, Gupta N. Late Presentation of Idiopathic Tympanic Membrane Ossification with External Auditory Canal Stenosis. Int J Otorhinolaryngol Clin 2015;7(3):141-143.

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