Contents
  1. The Mammalian Ear: Journal of Anatomy : Vol , No 2
  2. Hearables: Multimodal physiological in-ear sensing
  3. Tag: ear 05 pdf download
  4. Start managing your projects on the OSF today.

Tagged ear 05, ear 05 pdf download, ear stiftung, ear wizard, ear wizard erfahrungen, ear wizard test, ear-portal, earpods, headphones. The Ear Book (Bright & Early Board Books) By Al Perkins pdf download. The Ear Book .. Viewed times Last updated 05 May [PDF]. Any mishandling of the product (ex: false maneuvre, fall, shock, impact, immersion) or an inappropriate environment (ex: bad aeration, vibrations, exposure to.

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Ear 05 Pdf

Deutsche Welle „Learning by Ear “ African Entrepreneurs Episode 5: Julian Hello and welcome to our Learning by Ear series on African entrepreneurs. Learning by Ear –. Civil society and political commitment No. 5. Sects - Uganda. Feature: Gabriel Kahn. Editor: Sandrine Blanchard. Translation: Anne Thomas. PDF | In the ENT region 50% of the malformations affect the ear. Malformations of the outer and middle ear are predominantly unilateral (ca. %) and mostly.

Morphogenesis Abstract Jawed vertebrates have inner ears with three semicircular canals, the presence of which has been used as a key to understanding evolutionary relationships. Ostracoderms, the jawless stem gnathostomes, had only two canals and lacked the lateral canal 1 , 2 , 3. Lampreys, which are modern cyclostomes, are generally thought to possess two semicircular canals whereas the hagfishes—which are also cyclostomes—have only a single canal, which used to be regarded as a more primitive trait 1 , 4. However, recent molecular and developmental analyses have strongly supported the monophyly of cyclostomes 5 , 6 , 7 , which has left the evolutionary trajectory of the vertebrate inner ear unclear 8. Here we show the differentiation of the otic vesicle of the lamprey Lethenteron camtschaticum and inshore hagfish Eptatretus burgeri. This is the first time, to our knowledge, that the development of the hagfish inner ear is reported. We found that canal development in the lamprey starts with two depressions—which is reminiscent of the early developmental pattern of the inner ear in modern gnathostomes. These cyclostome otic vesicles show a pattern of expression of regulatory genes, including OTX genes, that is comparable to that of gnathosomes.

Both is the case only if an implant vibrates the ossicular chain and the cochlea is left intact, but not in other common stimulation modes 9 , 10 , 11 , 12 where an AMEI drives the round window or the cochlear fluid is directly stimulated by a direct acoustic cochlear implant DACI.

In a DACI application the stapes footplate is perforated to insert the tip of an actuator into the cochlea fluid. The DACI converts acoustical signals into vibrations to stimulate the cochlear fluid mechanically. If the round window is excited by an actuator, the ear is stimulated in reverse direction and the acoustic input impedance is different compared to the input impedance during acoustic stimulation, leading to an underestimation of the real stimulation output if stapes vibration is used 8.

In direct stimulation of the cochlear fluid with a DACI the stapes footplate is perforated and bypassed, making stapes vibration measurements meaningless. To estimate the output level of such stimulation in cadaveric TBs, the vibration responses of the round window is commonly measured by an LDV instead 13 , However, perforating the stapes footplate and opening the cochlea changes the acoustic input impedance of the inner ear and causes a strong change in the round window motion pattern above 1.

Therefore round window vibration measurements are unreliable to quantify the stimulation output of a DACI. A potential alternative method to quantify in cadaver studies the output level of an AMEI or DACI in all stimulation modes is the measurement of the difference in sound pressure between scala vestibuli SV and scala tympani ST 16 , two fluid filled canals in the cochlea.

The so called intra cochlea pressure difference ICPD has been shown to correlate with auditory evoked potentials in animals 17 , has been successfully measured during forward and reverse stimulation in TB experiments 8 , 16 , 18 , 19 , 20 , is considered as the input to the cochlea 19 and is measurable with off-the-shelf sensors The aim of this study was twofold. For this purpose, AMEI equivalent actuator output levels eq.

The Mammalian Ear: Journal of Anatomy : Vol , No 2

Materials and Methods The equivalent sound pressure level eq. This stimulation mode was chosen because stapes vibration measurement according to ASTM 1 is the recommended measure of cochlear excitation in this application. Additionally, results from cadaveric ears were compared with T2 actuator output levels obtained from clinical data.

Most of the methods used here were similar to previous studies 13 , 16 containing more detailed descriptions of the experimental setup. Temporal bone preparation Fourteen already frozen, anonymized human cadaveric TBs were obtained from the Institute for Pathology of the Hannover Medical School.

All TBs were harvested in autopsies and the donors were anonymous and no biographical donor data are known. Harvesting and use of the TBs was conducted in accordance with the Helsinki declaration and approved by the ethics committee of the Hannover Medical School approval No. All TBs were harvested within 48 h post mortem, immediately frozen at approx.

The stapes and the promontory were exposed by a mastoidectomy, a removal of the facial nerve and drilling of the bony rim of the round window niche overhang down to approx. During experiments the preparations were moistened with saline to avoid changes in mechanical behavior 1. Experimental setup TBs were fixed in a laboratory clamp and a custom-made sound application setup comprising a probe microphone ER-7C, Etymotic Research Inc.

This assembly was attached to a 3-axis micromanipulator MR, World Precision Instruments Germany GmbH, Germany allowing adjustments in all three spatial directions while monitoring the axial force by the force sensor. The entire setup was installed on a vibration isolated table LWB, Newport.

Intracochlear pressure measurement The method used for intracochlear sound pressure measurement is described in detail in a previous publication Figure 1 Temporal bone preparation for the incus stimulation. Full size image Experimental procedure Experiments were performed in TBs having middle ear transfer function within the modified acceptance range 6 of ASTM standard F 1 at 0.

First, the tympanic membrane was stimulated acoustically between 0. For technical limitation of the 4-Ch data acquisition ICPD and vibratory responses were measured sequentially. During the first stimulation the sound pressures P SV and P ST were measured by the pressure transducers and during the second stimulation the vibration of the stapes was measured by the LDV.

The acoustic input signal at the tympanic membrane was recorded both times by the probe microphone. Although amplitudes and phases of the input signal had minor differences during both stimulations maximum difference: 0.

After completing the acoustical stimulation, a hole of approx. The actuator stimulation was performed at different contact positions.

To define a zero position, the tip of the T2 actuator was advanced towards the laser hole until the tip almost touched the incus and the recording of the force sensor was zeroed.

At each position, the displayed force level was recorded and actuator stimulation and measurements were performed as follows. The actuator was electrically driven with the same sequence of sine wave signals previously used for the acoustical stimulation, having amplitudes of approx. Again amplitude and phase of the input signal had minor differences during both measurements maximum difference: 0.

From each experiment we had a set of measurement data at different positions and force levels. On average, the contact force was 3. After completing all measurements, the pressure transducers were removed and the correct positioning of the cochleostomies in SV and ST and the integrity of the basilar membrane were confirmed visually by dissection of the TB. Intraoperatively, the TLA is used to guide adjustment of the T2 actuator to the incus body by measuring its electrical impedance at the resonance frequency while the actuator is advanced In six tests the drop in impedance initial contact occurred between 1 and 7 mN 3.

Therefore we selected from the data set of each TB experiment that position where the contact force was closest to 4 mN. Electric input signals to the loudspeaker and to the actuator were generated at During measurement the signal-to-noise ratio SNR of the intracochlear pressure and vibratory responses at each stimulation frequency was calculated in LabVIEW using the average of the three adjacent FFT lines below and above as noise level estimate.

In a great majority of measurements an SNR of 20 to 60 dB was already reached with 30 averages and averaging more than 30 times was necessary in a few cases only. In brief, the unimplanted stapes displacement d U calculated from velocity measured by the LDV in response to ear canal sound pressure p T at the tympanic membrane was compared to the stapes displacement d A generated by the actuator attached to the incus driven by input voltage E.

At frequencies where no transformation value T d was given in Shaw et al. We assume that the loudness perception at bone conduction BC threshold and at direct threshold is the same.

Actuator output L E [eq. Data availability All data analyzed during this study are included in this published article and its Supplementary Information files. In other words, actuator output [eq. All clinically and experimentally determined actuator output levels presented here were normalized to a hypothetical actuator input voltage of 1 Vrms. Actuator output levels determined experimentally are shown for an actuator position with a coupling force of approx. Actuator output calculated from stapes motion 4 mN static coupling force Based on stapes vibration amplitude, the actuator produced in the individual TBs between 82 and eq.

The results were normally distributed Shapiro-Wilk test at all frequencies except at 3. The median output level was in the range of to eq. Figure 2 Actuator output eq. Actuator output level was normally distributed Shapiro-Wilk test at all frequencies except at 3. The median output level was between and eq. Above 2 kHz the individual results showed an increased inter-individual variability with outputs from 78 to eq.

The results were normally distributed Shapiro-Wilk test at all frequencies except 0. The median output levels were in the range of 88 to eq. Figure 3 Actuator output eq. Outputs were normally distributed Shapiro-Wilk test at all frequencies except at 0.

Second, stapes vibration is a valid measure of the input to the inner ear only in forward stimulation where the direction of sound transmission is identical to normal hearing and vibration of the stapes is the input to the inner ear 8.

Both is the case only if an implant vibrates the ossicular chain and the cochlea is left intact, but not in other common stimulation modes 9 , 10 , 11 , 12 where an AMEI drives the round window or the cochlear fluid is directly stimulated by a direct acoustic cochlear implant DACI. In a DACI application the stapes footplate is perforated to insert the tip of an actuator into the cochlea fluid.

The DACI converts acoustical signals into vibrations to stimulate the cochlear fluid mechanically. If the round window is excited by an actuator, the ear is stimulated in reverse direction and the acoustic input impedance is different compared to the input impedance during acoustic stimulation, leading to an underestimation of the real stimulation output if stapes vibration is used 8.

In direct stimulation of the cochlear fluid with a DACI the stapes footplate is perforated and bypassed, making stapes vibration measurements meaningless.

To estimate the output level of such stimulation in cadaveric TBs, the vibration responses of the round window is commonly measured by an LDV instead 13 , However, perforating the stapes footplate and opening the cochlea changes the acoustic input impedance of the inner ear and causes a strong change in the round window motion pattern above 1.

Therefore round window vibration measurements are unreliable to quantify the stimulation output of a DACI. A potential alternative method to quantify in cadaver studies the output level of an AMEI or DACI in all stimulation modes is the measurement of the difference in sound pressure between scala vestibuli SV and scala tympani ST 16 , two fluid filled canals in the cochlea.

The so called intra cochlea pressure difference ICPD has been shown to correlate with auditory evoked potentials in animals 17 , has been successfully measured during forward and reverse stimulation in TB experiments 8 , 16 , 18 , 19 , 20 , is considered as the input to the cochlea 19 and is measurable with off-the-shelf sensors The aim of this study was twofold.

For this purpose, AMEI equivalent actuator output levels eq. The equivalent sound pressure level eq. This stimulation mode was chosen because stapes vibration measurement according to ASTM 1 is the recommended measure of cochlear excitation in this application.

Additionally, results from cadaveric ears were compared with T2 actuator output levels obtained from clinical data. Most of the methods used here were similar to previous studies 13 , 16 containing more detailed descriptions of the experimental setup. All TBs were harvested in autopsies and the donors were anonymous and no biographical donor data are known.

Harvesting and use of the TBs was conducted in accordance with the Helsinki declaration and approved by the ethics committee of the Hannover Medical School approval No. The stapes and the promontory were exposed by a mastoidectomy, a removal of the facial nerve and drilling of the bony rim of the round window niche overhang down to approx. During experiments the preparations were moistened with saline to avoid changes in mechanical behavior 1. TBs were fixed in a laboratory clamp and a custom-made sound application setup comprising a probe microphone ER-7C, Etymotic Research Inc.

This assembly was attached to a 3-axis micromanipulator MR, World Precision Instruments Germany GmbH, Germany allowing adjustments in all three spatial directions while monitoring the axial force by the force sensor.

The entire setup was installed on a vibration isolated table LWB, Newport. The method used for intracochlear sound pressure measurement is described in detail in a previous publication Temporal bone preparation for the incus stimulation. Experiments were performed in TBs having middle ear transfer function within the modified acceptance range 6 of ASTM standard F 1 at 0. First, the tympanic membrane was stimulated acoustically between 0. For technical limitation of the 4-Ch data acquisition ICPD and vibratory responses were measured sequentially.

During the first stimulation the sound pressures P SV and P ST were measured by the pressure transducers and during the second stimulation the vibration of the stapes was measured by the LDV. The acoustic input signal at the tympanic membrane was recorded both times by the probe microphone. Although amplitudes and phases of the input signal had minor differences during both stimulations maximum difference: After completing the acoustical stimulation, a hole of approx.

The actuator stimulation was performed at different contact positions. To define a zero position, the tip of the T2 actuator was advanced towards the laser hole until the tip almost touched the incus and the recording of the force sensor was zeroed. At each position, the displayed force level was recorded and actuator stimulation and measurements were performed as follows.

The actuator was electrically driven with the same sequence of sine wave signals previously used for the acoustical stimulation, having amplitudes of approx. Again amplitude and phase of the input signal had minor differences during both measurements maximum difference: From each experiment we had a set of measurement data at different positions and force levels.

On average, the contact force was 3. After completing all measurements, the pressure transducers were removed and the correct positioning of the cochleostomies in SV and ST and the integrity of the basilar membrane were confirmed visually by dissection of the TB. Intraoperatively, the TLA is used to guide adjustment of the T2 actuator to the incus body by measuring its electrical impedance at the resonance frequency while the actuator is advanced In six tests the drop in impedance initial contact occurred between 1 and 7 mN 3.

Therefore we selected from the data set of each TB experiment that position where the contact force was closest to 4 mN. Electric input signals to the loudspeaker and to the actuator were generated at During measurement the signal-to-noise ratio SNR of the intracochlear pressure and vibratory responses at each stimulation frequency was calculated in LabVIEW using the average of the three adjacent FFT lines below and above as noise level estimate.

In brief, the unimplanted stapes displacement d U calculated from velocity measured by the LDV in response to ear canal sound pressure p T at the tympanic membrane was compared to the stapes displacement d A generated by the actuator attached to the incus driven by input voltage E.

Finally, all eq. At frequencies where no transformation value T d was given in Shaw et al. We assume that the loudness perception at bone conduction BC threshold and at direct threshold is the same.

Actuator output L E [eq. All data analyzed during this study are included in this published article and its Supplementary Information files. In other words, actuator output [eq. All clinically and experimentally determined actuator output levels presented here were normalized to a hypothetical actuator input voltage of 1 V rms.

Actuator output levels determined experimentally are shown for an actuator position with a coupling force of approx. The results were normally distributed Shapiro-Wilk test at all frequencies except at 3.

Actuator output eq. Actuator output level was normally distributed Shapiro-Wilk test at all frequencies except at 3. The results were normally distributed Shapiro-Wilk test at all frequencies except 0. Outputs were normally distributed Shapiro-Wilk test at all frequencies except at 0.

Actuator output levels eq. The median eq. The results were normally distributed Shapiro-Wilk test at all frequencies. Data points are missing at frequencies where the direct or bone conduction threshold was not or could not be measured. Number of patients contributing data at 0.

Hearables: Multimodal physiological in-ear sensing

Median eq. The difference between the actuator outputs calculated from stapes motion and ICPD was statistically not significant Wilcoxon Signed Rank Test , except at 0. Comparison of median actuator output levels eq. Actuator outputs measured in TBs and in patients were statistically compared at audiometric frequencies 0.

Tag: ear 05 pdf download

Actuator output level in TBs at 1. Median actuator output levels obtained in TBs and clinical results had similar frequency dependency Fig. The differences between the median eq. When normalized to ear canal sound pressure input level p T at the tympanic membrane, the magnitudes and phases of the ICPD measured during acoustical stimulation were mostly in good accordance with data from literature 19 Supplementary Figure 2.

Output levels in these studies were given as eq. SPLs at the tympanic membrane [eq. However, in the publication by Tringali et al. It may have contributed that 2 out of 5 TBs in Tringali et al.

To our knowledge, this is the first study quantifying the eq. As incus stimulation is within the scope of ASTM , eq. This discrepancy may be explained by the fact that the complex nature of stapes motion at higher frequencies as rocking motions are more likely to affect stapes vibration measured at a single location than ICPD that integrate pressure fields at a more remote location in the cochlea. Based on numerical simulations, rocking motion does not produce net volume displacement of the perilymph and has negligible effects on cochlear excitation Thus, rocking motion components measured at a single point with a 1-D single-point LDV may be misinterpreted as piston-like motions and contribute to the measured vibration amplitude.

Of course, this would have no effect on the eq. SPL calculation if the complex motion pattern of the stapes were identical in the acoustic reference stimulation and the mechanical stimulation. However, in our study the eq. Therefore we assume that, the pattern of the complex stapes motion at high frequencies changed when the T2 actuator vibrated the incus body in a direction different to the direction of incus motion during acoustic stimulation.

Under this assumption, the use of stapes vibration amplitudes measured with a 1-D single-point LDV as reference could lead to a slight overestimation of the real stimulation output as it is visible in our results Fig.

In contrast, ICPD considered as the input to the cochlea 19 is a result of the net volume displacement of the stapes footplate and should not be affected by stapes rocking motions. This assumption is confirmed by our study as the eq. Independent from the reference stapes motion or ICPD , all estimated eq.

SPL were close to the eq. Therefore we assume that ICPD is a better reference for eq. SPL estimation from cadaver studies that is not affected by altered stapes motion patterns at higher frequencies as discussed above. At the detection limit of the TLA static coupling force of approx.

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These results suggest that the post-operative coupling force in our patients was also approx. One potential reason for the presumably smaller force level in our patients may be that in our clinic the final contact position of the T2 actuator during surgery is determined not by using the TLA but by measuring the stapes vibration response with an LDV during actuator stimulation.

Based on our experience this method is more sensitive than using the TLA, because proper stapes vibration responses are measurable even at loading forces below 4 mN. Another reason might be a long-term relaxation of the ossicular chain in patients leading to a shift of the incus and a decreasing contact force. Long-term effects such as tissue growth around the actuator that may occur in patients could not be simulated in the TB experiments.

At least, an attenuating effect of surrounding tissue on the mechanical output of the AMEI actuator is unlikely These estimates were compared to each other and to audiometric data from patients treated with the same AMEI type and stimulation mode. This study demonstrates for the first time that both ICPD and stapes motion can be used as a valid measure to predict the clinically achievable loudness of AMEIs in cadaver studies.

However, ICPD as reference provided results matching the output from clinical data even better and has the advantage of being applicable to stimulation scenarios where the stapes footplate is not possible as reference. Publisher's note:

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