Effects of Body Position on the Auditory System

1972 ◽  
Vol 15 (2) ◽  
pp. 330-339 ◽  
Author(s):  
J. H. Macrae
Keyword(s):  
Hydrostatic Pressure ◽  
Tympanic Membrane ◽  
Auditory System ◽  
Middle Ear ◽  
Acoustic Impedance ◽  
Body Position ◽  
Upright Position ◽  
Tensor Tympani Muscle ◽  
Muscle Reflexes ◽  
Labyrinthine Fluids

Effects of body position on auditory threshold acuity, the acoustic impedance at the tympanic membrane, and the middle ear muscle reflexes were investigated at 150, 250, and 500 Hz. Relative to the values obtained in the seated upright position, threshold acuity was reduced, the resistive and reactive components of the acoustic impedance were greater, and the effects of stapedius and tensor tympani muscle contractions on the compliance at the tympanic membrane were reduced in the inverted (upside-down) position. The increase in acoustic impedance, which is probably due to an increase in the hydrostatic pressure of the labyrinthine fluids, accounted for only about half the decrease in threshold acuity.

Body Inversion and the Acoustic Immittance of the Ear

1974 ◽  
Vol 17 (2) ◽  
pp. 310-320 ◽  
Author(s):  
J. H. Macrae
Keyword(s):  
Middle Ear ◽  
Atmospheric Pressure ◽  
Upright Position ◽  
Air Pressure ◽  
Tone Frequency ◽  
Reactive Component ◽  
Inverted Position ◽  
External Meatus ◽  
Resistive Component ◽  
Labyrinthine Fluids

The effect of body inversion on the acoustic immittance of normal ears was investigated by means of admittance tympanometry at a probe-tone frequency of 660 Hz. In the upright position, maximum acoustic admittance at the tympanic membrane occurred when the air pressure in the external meatus was close to atmospheric pressure. In the inverted position, the admittance at the membrane was considerably reduced when the meatal air was at atmospheric pressure and maximum admittance occurred at a meatal air pressure of about 53 mm H 2 O, with the resistive component reduced and the reactive component slightly increased relative to their values in the upright position. When the middle-ear air pressure in the inverted position was equalized with the ambient atmospheric pressure, the maximum admittance at the membrane occurred at a meatal air pressure of 10–20 mm H 2 O and the reduction in conductance and slight increase in susceptance persisted. It was concluded that the effect of body inversion on the acoustic immittance of the ear is due largely to an increase in the air pressure in the middle-ear cavity (which is probably produced by an increase in the volume of the mucosa lining the cavity) and to a small extent to another overpressure which probably occurs in the labyrinthine fluids.

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 Recovery from tympanic membrane perforation: Effects on membrane thickness, auditory thresholds, and middle ear transmission

2019 ◽  
Vol 384 ◽  
pp. 107813 ◽  
Author(s):  
Lingling Cai ◽  
Glenna Stomackin ◽  
Nicholas M. Perez ◽  
Xiaohui Lin ◽  
Timothy T. Jung ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Tympanic Membrane Perforation ◽  
Membrane Thickness ◽  
Auditory Thresholds ◽  
Membrane Perforation

Causes of failure of combined approach tympanoplasty in the treatment of acquired cholesteatomas of the middle ear and the mastoid

1995 ◽  
Vol 109 (8) ◽  
pp. 710-712 ◽  
Author(s):  
T. R. Kapur
Keyword(s):  
Tympanic Membrane ◽  
Eustachian Tube ◽  
Middle Ear ◽  
Squamous Epithelium ◽  
Combined Approach ◽  
Tube Obstruction ◽  
Incomplete Removal ◽  
Tube Dysfunction ◽  
Cause Of Failure ◽  
Causes Of Failure

AbstractForty cases of failed combined approach tympanoplasty were analysed. The commonest cause of failure was adhesions between the facial ridge and the tympanic membrane, causing segmental attico-mastoid malaeration in 51.3 per cent of cases followed-up continually. Other causes were, large dermoids, incomplete removal of squamous epithelium, and eustachian tube obstruction. Eustachian tube dysfunction did not appear to be a major cause of failure.

Acoustic Neuromas and the Acoustic Impedance of the Ear

1973 ◽  
Vol 38 (3) ◽  
pp. 345-353 ◽  
Author(s):  
J. H. Macrae
Keyword(s):  
Tympanic Membrane ◽  
Acoustic Neuroma ◽  
Acoustic Impedance ◽  
Theoretical Calculations ◽  
Low Frequencies ◽  
Cochlear Duct ◽  
Acoustic Neuromas ◽  
Affected Side ◽  
Contralateral Ear ◽  
Conductive System

The acoustic impedance at the tympanic membrane was measured at frequencies in the range 100–1000 Hz and found to be abnormal on the affected side in four patients with acoustic neuroma. In all four the resistance was abnormally high at low frequencies on the affected side, and in three the reactance of the affected ear was raised relative to that of the contralateral ear, particularly at low frequencies. The abnormality is attributed to an increase in the input acoustic impedance of the cochlea produced by the increase in protein content of the cochlear fluids and dilatation of the cochlear duct known to occur in acoustic neuroma. This explanation is supported by theoretical calculations carried out on an electric analogue of the conductive system, and it is suggested that similar abnormalities in the acoustic impedance at the tympanic membrane might occur in other pathologies which produce abnormal mechanical conditions in the cochlea.

Anatomical Effects of Sudden Middle Ear Pressure Changes

1979 ◽  
Vol 88 (3) ◽  
pp. 368-376 ◽  
Author(s):  
A. Axelsson ◽  
J. Miller ◽  
M. Silverman
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Round Window ◽  
Applied Pressure ◽  
Positive Pressure ◽  
Air Bubbles ◽  
Scala Tympani ◽  
Middle Ear Pressure ◽  
Contralateral Ear ◽  
Pressure Changes

Acute middle ear (ME) and inner ear changes following brief unilateral phasic ME pressure changes (up to ± 6000/mm H2O) were studied in the guinea pig. Middle ear findings included perforation of the tympanic membrane, serous and serosanguinous exudate and hemorrhage of tympanic membrane and periosteal vessels. Changes were related to magnitude of applied pressure. Perforation and hemorrhage were more commonly seen with negative rather than positive pressure. Air bubbles behind the round window were seen with positive pressures. Occasional distortion, but never perforation of the round window, was noted. Hemorrhage of the scala tympani was observed with both positive and negative pressures; scala vestibuli hemorrhage was found with negative ME pressure. In some instances pressure direction and magnitude related changes were seen in the contralateral ear.

Bioengineering. Effect of Depth of Conical-Shaped Tympanic Membrane on Middle-Ear Sound Transmission.

2001 ◽  
Vol 44 (4) ◽  
pp. 1097-1102 ◽  
Author(s):  
Takuji KOIKE ◽  
Hiroshi WADA ◽  
Toshimitsu KOBAYASHI
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Sound Transmission

Audiological findings in glomus tumours

1997 ◽  
Vol 111 (3) ◽  
pp. 218-222 ◽  
Author(s):  
William W. Qiu ◽  
Shengguang S. Yin ◽  
Fred J. Stucker ◽  
Mardjohan Hardjasudarma
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Auditory System ◽  
Middle Ear ◽  
Otoacoustic Emissions ◽  
Cerebellopontine Angle ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

AbstractGlomus tumours involving the middle ear and the cerebellopontine angle are reported with emphasis on audiological findings. Magnetic resonance imaging (MRI), angiographic and pathological results are presented. Audiological tests, including impedance audiometry, evoked otoacoustic emissions and auditory brainstem responses, are valuable in evaluation of the effect of glomus tumours on the auditory system as well as their pathological extent.

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