Effects of pars flaccida on sound conduction in ears of Mongolian gerbil: acoustic and anatomical measurements

Teoh, Su Wooi; Flandermeyer, Deborah T.; Rosowski, John J.

doi:10.1016/s0378-5955(97)00002-6

Cited by 55 publications

(42 citation statements)

References 41 publications

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“…These in-phase motions of the TM at low frequencies are consistent with observations from others in cats (Decraemer et al, 1989(Decraemer et al, , 1999 and humans (Cheng et al 2010). At 0.2 kHz, TM #1 also shows a small area of large displacement superior to the manubrium; this region almost certainly represents low-frequency motion of the pars flaccida of the TM (Kohll€ offel, 1984;Teoh et al, 1997).…”

Section: Resultssupporting

confidence: 89%

Wave motion on the surface of the human tympanic membrane: Holographic measurement and modeling analysis

Cheng

Hamade

Merchant

et al. 2013

The Journal of the Acoustical Society of America

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Sound-induced motions of the surface of the tympanic membrane (TM) were measured using stroboscopic holography in cadaveric human temporal bones at frequencies between 0.2 and 18 kHz. The results are consistent with the combination of standing-wave-like modal motions and traveling-wavelike motions on the TM surface. The holographic techniques also quantified sound-induced displacements of the umbo of the malleus, as well as volume velocity of the TM. These measurements were combined with sound-pressure measurements near the TM to compute middle-ear input impedance and power reflectance at the TM. The results are generally consistent with other published data. A phenomenological model that behaved qualitatively like the data was used to quantify the relative magnitude and spatial frequencies of the modal and traveling-wave-like displacement components on the TM surface. This model suggests the modal magnitudes are generally larger than those of the putative traveling waves, and the computed wave speeds are much slower than wave speeds predicted by estimates of middle-ear delay. While the data are inconsistent with simple modal displacements of the TM, an alternate model based on the combination of modal motions in a lossy membrane can also explain these measurements without invoking traveling waves.

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Section: Resultssupporting

confidence: 89%

Wave motion on the surface of the human tympanic membrane: Holographic measurement and modeling analysis

Cheng

Hamade

Merchant

et al. 2013

The Journal of the Acoustical Society of America

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“…Figure 3 shows the mean P U / P EC ratio for the four later MEEI ears at three EC locations that span the range of P EC measurement locations in the other ears: approximately 3.0 mm from the umbo, near the bony EC entrance; and approximately 2.5 and 2.0 mm from the umbo. P U / P EC at each of these three locations was remarkably similar among ears ͓as revealed by the small standard deviations ͑s.d.͒-right axis͔, consistent with previous acoustical measurements in gerbil ͑see, for example, Ravicz et al, 1992Ravicz et al, , 1996Teoh et al, 1997͒. The variance in ͉P U / P EC ͉ at each location was due primarily to broadband differences-the overall frequency dependence and the frequencies of magnitude peaks and notches varied little among ears.…”

Section: Computation Of Transfer Admittance From Stapes Velocity Asupporting

confidence: 86%

Gerbil middle-ear sound transmission from 100Hzto60kHz

Ravicz

Cooper

Rosowski

2008

The Journal of the Acoustical Society of America

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Middle-ear sound transmission was evaluated as the middle-ear transfer admittance H MY ͑the ratio of stapes velocity to ear-canal sound pressure near the umbo͒ in gerbils during closed-field sound stimulation at frequencies from 0.1 to 60 kHz, a range that spans the gerbil's audiometric range. Similar measurements were performed in two laboratories. The H MY magnitude ͑a͒ increased with frequency below 1 kHz, ͑b͒ remained approximately constant with frequency from 5 to 35 kHz, and ͑c͒ decreased substantially from 35 to 50 kHz. The H MY phase increased linearly with frequency from 5 to 35 kHz, consistent with a 20-29 s delay, and flattened at higher frequencies. Measurements from different directions showed that stapes motion is predominantly pistonlike except in a narrow frequency band around 10 kHz. Cochlear input impedance was estimated from H MY and previously-measured cochlear sound pressure. Results do not support the idea that the middle ear is a lossless matched transmission line. Results support the ideas that ͑1͒ middle-ear transmission is consistent with a mechanical transmission line or multiresonant network between 5 and 35 kHz and decreases at higher frequencies, ͑2͒ stapes motion is pistonlike over most of the gerbil auditory range, and ͑3͒ middle-ear transmission properties are a determinant of the audiogram.

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“…The effect of middle ear pressure on TM mobility has been investigated in human temporal bones and animals (Teoh et al, 1997;Lee and Rosowski, 2001;Rosowski and Lee, 2002;Murakami et al, 1997;Dirckx and Decraemer, 1992;Huttenbrink 1998;Gan et al, 2006;Dai et al, 2007). The results of Murakami et al and Gan et al show that the middle ear pressure mainly decreased the TM movement at low frequencies (f <1k Hz).…”

Section: Introductionmentioning

confidence: 99%

Combined effect of fluid and pressure on middle ear function

2008

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In our previous studies, the effects of effusion and pressure on sound transmission were investigated separately. The aim of this study is to investigate the combined effect of fluid and pressure on middle ear function. An otitis media with effusion model was created by injecting saline solution and air pressure simultaneously into the middle ear of human temporal bones. Tympanic membrane displacement in response to 90 dB SPL sound input was measured by a laser vibrometer and the compliance of the middle ear was measured by a tympanometer. The movement of the tympanic membrane at the umbo was reduced up to 17 dB by the combination of fluid and pressure in the middle ear over the auditory frequency range. The fluid and pressure effects on the umbo movement in the fluid-pressure combination are not additive. The combined effect of fluid and pressure on the umbo movement is different compared with that of only fluid or pressure change in the middle ear. Negative pressure in fluid-pressure combination had more effect on middle ear function than positive pressure. Tympanometry can detect the middle ear pressure of the fluid-pressure combination. This study provides quantitative information for analysis of the combined effect of fluid and pressure on tympanic membrane movement.

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Effects of pars flaccida on sound conduction in ears of Mongolian gerbil: acoustic and anatomical measurements

Cited by 55 publications

References 41 publications

Wave motion on the surface of the human tympanic membrane: Holographic measurement and modeling analysis

Wave motion on the surface of the human tympanic membrane: Holographic measurement and modeling analysis

Gerbil middle-ear sound transmission from 100Hzto60kHz

Combined effect of fluid and pressure on middle ear function

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