On Middle Ear Pressure

Flisberg, Knut; Ingelstedt, Sven; Örtegren, Urban

doi:10.3109/00016486309139992

Cited by 90 publications

(24 citation statements)

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“…Earlier, Flisberg et al (1963) reported data from individual subjects showing a similar effect of negative MEP on hearing thresholds. However, they used an invasive approach (a mastoid puncture procedure) to vary the MEP.…”

Section: Effects Of Negative Mepmentioning

confidence: 60%

“…However, this difference should be small because of the following: (1) air volume change is very small when the air pressure is altered in the middle ear, according to a human cadaver study by Dai et al (2008), which showed a 0.9% change in volume by 200 mm H 2 O and a 0.6% change by Ϫ200 mm H 2 O; (2) air density is not reduced so much under a negative MEP because of the adaptive retraction of the tympanic membrane; and (3) a positive ECP does not yield an equivalent positive MEP because of the limit of volume displacement of the tympanic membrane relative to its elasticity. It has been verified by Flisberg et al (1963) in a human study that Ͻ10% of an experimentally introduced MEP at Ϯ50 mm Hg transfers to the closed ear canal. In an animal study (Konradsson et al 1997), it was also estimated that approximately 20 to 25% of ambient air pressure at Ϫ40 to Ϫ52 mm Hg in a pressure chamber transferred into the middle ear (1 mm Hg Ϸ 13.60 mm H 2 O and 1 mm H 2 O ϭ 0.98 daPa).…”

Section: Implications For Certain Issues On Middle Ear Dynamicsmentioning

confidence: 83%

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Ear Canal Pressure Variations Versus Negative Middle Ear Pressure: Comparison Using Distortion Product Otoacoustic Emission Measurement in Humans

Sun

2012

Ear &Amp; Hearing

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Effects of negative MEP and ECP variations on DPOAEs in human ears are comparable, to a great extent, to findings from previous studies on hearing sensitivity in humans and tympanic membrane vibration at the umbo in human temporal bones. The present study demonstrates that positive ECP can be used to simulate negative MEP in research on the middle ear function in live humans. Results also suggest that long-lasting beliefs regarding the ECP effect on the middle ear conduction should be amended: (1) only positive ECP, not negative ECP, attenuates sound transmission more for low frequencies than for high frequencies, and (2) positive ECP has a greater effect than negative ECP only for low frequencies and not for high frequencies. Discussion of the present results together with those from previous studies sheds light on the middle ear dynamics under diverse pressure changes across the tympanic membrane and proposes that distorted configuration of the tympanic membrane and ossicular chain is the key factor in the effect of MEP or ECP on the middle ear sound transmission for low frequencies.

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Section: Effects Of Negative Mepmentioning

confidence: 60%

Section: Implications For Certain Issues On Middle Ear Dynamicsmentioning

confidence: 83%

Ear Canal Pressure Variations Versus Negative Middle Ear Pressure: Comparison Using Distortion Product Otoacoustic Emission Measurement in Humans

Sun

2012

Ear &Amp; Hearing

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“…These quasi-static pressure variations are orders of magnitude larger than the highest sound pressures, and have been measured both indirectly and directly by many authors (e.g., Flisberg et al 1961;Hergils and Magnuson 1985;Tideholm et al 1996). Recently, we reported results of ME pressure monitoring in intact human MEs (Dirckx et al 2000) and found pressure changes up to 1 kPa over intervals of hours and minutes (e.g., when rising from recumbent to upright position).…”

Section: Introductionmentioning

confidence: 67%

Quasi-static Transfer Function of the Rabbit Middle Ear‚ Measured with a Heterodyne Interferometer with High-Resolution Position Decoder

Dirckx

Buytaert

Decraemer

2006

JARO

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Due to changes in ambient pressure and to the gasexchange processes in the middle ear (ME) cavity, the ear is subject to ultra-low-frequency pressure variations, which are many orders of magnitude larger than the loudest acoustic pressures. Little quantitative data exist on how ME mechanics deals with these large quasi-static pressure changes and because of this lack of data, only few efforts could be made to incorporate quasi-static behavior into computer models. When designing and modeling ossicle prostheses and implantable ME hearing aids, the effects of large ossicle movements caused by quasistatic pressures should be taken into account. We investigated the response of the ME to slowly varying pressures by measuring the displacement of the umbo and the stapes in rabbit with a heterodyne interferometer with position decoder. Displacement versus pressure curves were obtained at linear pressure change rates between 200 Pa/s and 1.5 kPa/s, with amplitude T2.5 kPa. The change in stapes position associated with a pressure change is independent of pressure change rate (34 mm peak-to-peak at T2.5 kPa). The stapes displacement versus pressure curves are highly nonlinear and level off for pressures beyond T1 kPa. Stapes motion shows no measurable hysteresis at 1.5 kPa/s, which demonstrates that the annular ligament has little viscoelasticity. Hysteresis increases strongly at the lowest pressure change rates. The stapes moves in phase with the umbo and with pressure, but the sense of rotation of the hysteresis loop of stapes is phase inversed. Stapes motion is not a simple lever ratio mimic of umbo motion, but is the consequence of complex changes in ossicle joints and ossicle position. The change in umbo position produced by a T2.5 kPa pressure change decreases with increasing rate from 165 mm at 200 Pa/s to 118 mm at 1.5 kPa/s. Umbo motion already shows significant hysteresis at 1.5 kPa/s, but hysteresis increases further as pressure change rate decreases. We conclude that in the quasi-static regime, ossicle movement is not only governed by viscoelasticity, but that other effects become dominant as pressure change rate decreases below 1 kPa/s. The increasing hysteresis can be caused by increasing friction as speed of movement decreases, and incorporating speed-dependent friction coefficients will be essential to generate realistic models of ossicle movements at slow pressure change rates.

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“…One of those mechanisms is the development of negative pressure inside the cavity. Flisberg et al (1963) showed that, with a negative pressure of 20-30 mmHg, 15 min was enough for transudation to start in the human ear. Hiraide and Paparella (1972) and Hiraide and Eriksson (1978) reported that as little as 1 min at −5 mmHg in guinea pigs caused transudation.…”

Section: Pars Flaccida Retractionmentioning

confidence: 99%

Experimental Study of Vibrations of Gerbil Tympanic Membrane with Closed Middle Ear Cavity

Maftoon

Funnell

Daniel

et al. 2013

JARO

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The purpose of the present work is to investigate the spatial vibration pattern of the gerbil tympanic membrane (TM) as a function of frequency. In vivo vibration measurements were done at several locations on the pars flaccida and pars tensa, and along the manubrium, on surgically exposed gerbil TMs with closed middle ear cavities. A laser Doppler vibrometer was used to measure motions in response to audio frequency sine sweeps in the ear canal. Data are presented for two different pars flaccida conditions: naturally flat and retracted into the middle ear cavity. Resonance of the flat pars flaccida causes a minimum and a shallow maximum in the displacement magnitude of the manubrium and pars tensa at low frequencies. Compared with a flat pars flaccida, a retracted pars flaccida has much lower displacement magnitudes at low frequencies and does not affect the responses of the other points. All manubrial and pars tensa points show a broad resonance in the range of 1.6 to 2 kHz. Above this resonance, the displacement magnitudes of manubrial points, including the umbo, roll off with substantial irregularities. The manubrial points show an increasing displacement magnitude from the lateral process toward the umbo. Above 5 kHz, phase differences between points along the manubrium start to become more evident, which may indicate flexing of the tip of the manubrium or a change in the vibration mode of the malleus. At low frequencies, points on the posterior side of the pars tensa tend to show larger displacements than those on the anterior side. The simple low-frequency vibration pattern of the pars tensa becomes more complex at higher frequencies, with the breakup occurring at between 1.8 and 2.8 kHz. These observations will be important for the development and validation of middle ear finite-element models for the gerbil.

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On Middle Ear Pressure

Cited by 90 publications

References 0 publications

Ear Canal Pressure Variations Versus Negative Middle Ear Pressure: Comparison Using Distortion Product Otoacoustic Emission Measurement in Humans

Ear Canal Pressure Variations Versus Negative Middle Ear Pressure: Comparison Using Distortion Product Otoacoustic Emission Measurement in Humans

Quasi-static Transfer Function of the Rabbit Middle Ear‚ Measured with a Heterodyne Interferometer with High-Resolution Position Decoder

Experimental Study of Vibrations of Gerbil Tympanic Membrane with Closed Middle Ear Cavity

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