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Mixed hearing loss associated with a sensorineural component and an impaired conductive mechanism for sound from the external ear canal to the cochlea represents a challenge for rehabilitation using either surgery or traditional hearing amplification. Direct stimulations of the ossicular chain and the round window (RW) membrane have allowed an improved hearing in this population. The authors review the developments in basic and clinical research that have allowed the exploration of new routes for inner ear stimulation. Similar changes occur in the electrophysiological measures in response to auditory stimulation through the traditional route and direct mechanical stimulation of the RW. The latter has proven to be very effective as a means of hearing rehabilitation in a group of patients with significant difficulties with hearing and communication.

OBJECTIVES: To compare contralateral to ipsilateral stimulation with percutaneous and transcutaneous bone conduction implants. BACKGROUND: Bone conduction implants (BCIs) effectively treat conductive and mixed hearing losses. In some cases, such as in single-sided deafness (SSD), the BCI is implanted contralateral to the remaining healthy ear in an attempt to restore some of the benefits provided by binaural hearing. While the benefit of contralateral stimulation have been shown in at least some patients, it is not clear what cues or mechanisms contribute to this function. Previous studies have investigated the motion of the ossicular chain, skull, and round window in response to bone vibration. Here, we extend those reports by reporting simultaneous measurements of cochlear promontory velocity and intracochlear pressures during bone conduction stimulation with two common BCI attachments, and directly compare ipsilateral to contralateral stimulation. METHODS: Fresh-frozen whole human heads were prepared bilaterally with mastoidectomies. Intracochlear pressure (P(IC)) in the scala vestibuli (P(SV)) and tympani (P(ST)) was measured with fiber optic pressure probes concurrently with cochlear promontory velocity (V(Prom)) via laser Doppler vibrometry during stimulation provided with a closed-field loudspeaker or a bone conduction implant (BCI). Stimuli were pure tones between 120 – 10240 Hz, and response magnitudes and phases for P(IC) and V(Prom) were measured for air and bone conducted sound presentation. RESULTS: Contralateral stimulation produced lower response magnitudes and longer delays than ipsilateral in all measures, particularly for high frequency stimulation. Contralateral response magnitudes were lower than ipsilateral response magnitudes by up to 10–15 dB above ~2 kHz for a skin-penetrating abutment, which increased to 25–30 dB and extended to lower frequencies when applied with a transcutaneous (skin drive) attachment. CONCLUSION: Transcranial attenuation and delay suggest that ipsilateral stimulation will be dominant for frequencies over ~1 kHz, and that complex phase interactions will occur during bilateral or bimodal stimulation. These effects indicate a mechanism by which bilateral users could gain some bilateral advantage.

Beginning in the late 20th century, implantable hearing aids were developed and used as an alternative for individuals who were unable to tolerate conventional hearing aids. Since that time, several devices have been developed, with four currently remaining on the international market (Med‐el Vibrant Soundbridge, Envoy Esteem, Ototronix MAXUM, and Cochlear Carina). This review will briefly examine the history of middle ear implant development, describe current available devices, evaluate the benefits and limits of the technology, and consider the future directions of research in the field of implantable hearing aids.

Previous genetic studies on susceptibility to otitis media and airway infections have focused on immune pathways acting within the local mucosal epithelium, and outside of allergic rhinitis and asthma, limited studies exist on the overlaps at the gene, pathway or network level between the upper and lower airways. In this report, we compared [1] pathways identified from network analysis using genes derived from published genome-wide family-based and association studies for otitis media, sinusitis, and lung phenotypes, to [2] pathways identified using differentially expressed genes from RNA-sequence data from lower airway, sinus, and middle ear tissues, in particular cholesteatoma tissue compared to middle ear mucosa. For otitis media, a large number of genes (n = 1,806) were identified as differentially expressed between cholesteatoma and middle ear mucosa, which in turn led to the identification of 68 pathways that are enriched in cholesteatoma. Two differentially expressed genes CR1 and SAA1 overlap in middle ear, sinus, and lower airway samples and are potentially novel genes for otitis media susceptibility. In addition, 56 genes were differentially expressed in both tissues from the middle ear and either sinus or lower airways. Pathways that are common in upper and lower airway diseases, whether from published DNA studies or from our RNA-sequencing analyses, include chromatin organization/remodeling, endocytosis, immune system process, protein folding, and viral process. Taken together, our findings from genetic susceptibility and differential tissue expression studies support the hypothesis that the unified airway theory wherein the upper and lower respiratory tracts act as an integrated unit also applies to infectious and nonallergic airway epithelial disease. Our results may be used as reference for identification of genes or pathways that are relevant to upper and lower airways, whether common across sites, or unique to each disease.

HYPOTHESIS: Insertion of cochlear implant electrodes generates transient pressure spikes within the vestibular labyrinth equivalent to high intensity acoustic stimuli. BACKGROUND: Though cochlear implant (CI) surgery is regarded as having low-risk of impacting the vestibular system, several studies have documented changes in vestibular function after implantation. The mechanism of these changes is not understood. We have previously established that large, potentially-damaging pressure transients can be generated in the cochlea during electrode insertion, but whether pressure transients occur within the vestibular labyrinth has yet to be determined. Here, we quantify the exposure of the vestibular system to potentially-damaging pressure transients during CI surgery. METHODS: Five human cadaveric heads were prepared with an extended facial recess and implanted sequentially with eight different CI electrode styles via a round window approach. Fiber-optic sensors measured intralabyrinthine pressures in scala vestibuli (SV), scala tympani (ST), and the lateral semicircular canal (LSCC) during insertions. RESULTS: Electrode insertion produced a range of high-intensity pressure spikes simultaneously in the cochlea and LSCC with all electrodes tested. Pressure transients recorded were found to be significantly higher in the vestibular labyrinth than the cochlea and occurred at peak levels known to cause acoustic trauma. CONCLUSION: Insertion of CI electrodes can produce transients in intralabyrinthine fluid pressure levels equivalent to high-intensity, impulsive acoustic stimuli. Results from this investigation affirm the importance of atraumatic surgical techniques and suggest that in addition to the cochlea, the vestibular system is potentially exposed to damaging fluid pressure waves during cochlear implantation.

The stapes is held in the oval window by the stapedial annular ligament (SAL), which restricts total peak-to-peak displacement of the stapes. Previous studies have suggested that for moderate (< 130 dB SPL) sound levels intracochlear pressure (PIC), measured at the base of the cochlea far from the basilar membrane, increases directly proportionally with stapes displacement (DStap), thus a current model of impulse noise exposure (the Auditory Hazard Assessment Algorithm for Humans, or AHAAH) predicts that peak PIC will vary linearly with DStap up to some saturation point. However, no direct tests of DStap, or of the relationship with PIC during such motion, have been performed during acoustic stimulation of the human ear. In order to examine the relationship between DStap and PIC to very high level sounds, measurements of DStap and PIC were made in cadaveric human temporal bones. Specimens were prepared by mastoidectomy and extended facial recess to expose the ossicular chain. Measurements of PIC were made in scala vestibuli (PSV) and scala tympani (PST), along with the SPL in the external auditory canal (PEAC), concurrently with laser Doppler vibrometry (LDV) measurements of stapes velocity (VStap). Stimuli were moderate (~100 dB SPL) to very high level (up to ~170 dB SPL), low frequency tones (20–2560 Hz). Both DStap and PSV increased proportionally with sound pressure level in the ear canal up to approximately ~150 dB SPL, above which both DStap and PSV showed a distinct deviation from proportionality with PEAC. Both DStap and PSV approached saturation: DStap at a value exceeding 150 μm, which is substantially higher than has been reported for small mammals, while PSV showed substantial frequency dependence in the saturation point. The relationship between PSV and DStap remained constant, and cochlear input impedance did not vary across the levels tested, consistent with prior measurements at lower sound levels. These results suggest that PSV sound pressure holds constant relationship with DStap, described by the cochlear input impedance, at these, but perhaps not higher, stimulation levels. Additionally, these results indicate that the AHAAH model, which was developed using results from small animals, underestimates the sound pressure levels in the cochlea in response to high level sound stimulation, and must be revised.

Hypothesis: A cochlear implant electrode within the cochlea contributes to the air-bone gap (ABG) component of postoperative changes in residual hearing after electrode insertion. Background: Preservation of residual hearing after cochlear implantation has gained importance as simultaneous electric-acoustic stimulation allows for improved speech outcomes. Postoperative loss of residual hearing has previously been attributed to sensorineural changes; however, presence of increased postoperative ABG remains unexplained and could result in part from altered cochlear mechanics. Here, we sought to investigate changes to these mechanics via intracochlear pressure measurements before and after electrode implantation to quantify the contribution to postoperative ABG. Methods: Human cadaveric heads were implanted with titanium fixtures for bone conduction transducers. Velocities of stapes capitulum and cochlear promontory between the two windows were measured using single-axis laser Doppler vibrometry and fiber-optic sensors measured intracochlear pressures in scala vestibuli and tympani for air- and bone-conducted stimuli before and after cochlear implant electrode insertion through the round window. Results: Intracochlear pressures revealed only slightly reduced responses to air-conducted stimuli consistent with previous literature. No significant changes were noted to bone-conducted stimuli after implantation. Velocities of the stapes capitulum and the cochlear promontory to both stimuli were stable after electrode placement. Conclusion: Presence of a cochlear implant electrode causes alterations in intracochlear sound pressure levels to air, but not bone, conducted stimuli and helps to explain changes in residual hearing noted clinically. These results suggest the possibility of a cochlear conductive component to postoperative changes in hearing sensitivity.

This study examined the safety and efficacy of a fully implantable active middle ear (AMEI) system. Outcome measures assessed AMEI performance compared with an optimally fitted conventional hearing aid (CHA). Fifty adults with stable, symmetric moderate-to-severe sensorineural hearing loss were implanted at 9 ambulatory settings. Consonant-Nucleus-Consonant (CNC) words, Bamford-Kowel-Bench Speech in Noise test (BKB-SIN), Abbreviated Profile of Hearing Aid Benefit (APHAB), and unaided hearing thresholds in the implanted ear were compared to baseline measures obtained using a personal CHA. Changes in thresholds were observed from pre- to 12-month postoperative assessments. CNC word scores decreased (within 10%), and the BKB-SIN showed no change from pre- to 12-month postoperative time points. The APHAB revealed improvement. Findings suggest no difference in performance between an appropriately fit CHA and the AMEI at 12 months. This study indicates AMEIs have the potential to help individuals who choose not to use CHAs.

HYPOTHESIS: Simulated otitis media with effusion reduces intracochlear pressures comparable to umbo velocity. BACKGROUND: Otitis media with effusion is a common cause of temporary hearing loss, particularly in children, that can produce conductive deficits of 30–40 dB. Previous studies have measured the effects of simulated effusion on ossicular mechanics; however, no studies have measured cochlear stimulation directly during effusion. Here, we compare pressures in the scala vestibuli and tympani to umbo velocity, before and after induction of simulated effusion in cadaveric human specimens. METHODS: Eight cadaveric, hemi-cephalic human heads were prepared with complete mastoidectomies. Intracochlear pressures were measured with fiber optic pressure probes, and umbo velocity measured via laser Doppler vibrometry (LDV). Stimuli were pure tones (0.1 – 14 kHz) presented in the ear canal via a custom speculum modified to accept speaker and microphone tubing, and sealed with a glass cover slip. Effusion was simulated by filling the mastoid cavity and middle ear space with water. RESULTS: Acoustic stimulation with middle ear effusion resulted in decreased umbo velocity up to ~26 dB, whereas differential pressure at the base of the cochlea, the driving force to the basilar membrane, decreased by only ~16 db. CONCLUSION: Simulating effusion leads to a frequency-dependent reduction in intracochlear sound pressure levels consistent with audiological presentation and prior reports. Results reveal that intracochlear pressure measurements (P(SV) & P(ST)) decrease less than expected, and less than the decrease observed in the differential pressure (P(Diff)). The observed decrease in umbo velocity is greater than in the differential intracochlear pressures, suggesting that umbo velocity overestimates the induced conductive hearing loss. These results suggest that an alternate sound conduction pathway transmits sound to the inner ear during effusion.

Hypothesis Cochlear implants (CIs) designed for hearing preservation will not alter mechanical properties of the middle and inner ears as measured by intracochlear pressure (P(IC)) and stapes velocity (Vstap). Background CIs designed to provide combined electroacoustic stimulation are now available. To maintain functional acoustic hearing, it is important to know if a CI electrode can alter middle or inner ear mechanics because any alteration could contribute to elevated low-frequency thresholds in electroacoustic stimulation patients. Methods Seven human cadaveric temporal bones were prepared, and pure-tone stimuli from 120 Hz to 10 kHz were presented at a range of intensities up to 110 dB sound pressure level. P(IC) in the scala vestibuli (P(SV)) and tympani (PST) were measured with fiber-optic pressure sensors concurrently with VStap using laser Doppler vibrometry. Five CI electrodes from two different manufacturers with varying dimensions were inserted via a round window approach at six different depths (16-25 mm). Results The responses of P(IC) and VStap to acoustic stimulation were assessed as a function of stimulus frequency, normalized to sound pressure level in the external auditory canal, at baseline and electrode-inserted conditions. Responses measured with electrodes inserted were generally within approximately 5 dB of baseline, indicating little effect of CI electrode insertion on P(IC) and VStap. Overall, mean differences across conditions were small for all responses, and no substantial differences were consistently visible across electrode types. Conclusion Results suggest that the influence of a CI electrode on middle and inner ear mechanics is minimal despite variation in electrode lengths and configurations.

HYPOTHESIS Bone-anchored hearing systems (BAHSs) provide sound location-dependent input to the normal ear for reducing the head shadow effect in the case of single-sided deafness (SSD). BACKGROUND Patients with SSD can be fit with a BAHS positioned on the impaired side. Despite successful outcomes and some reports of spatial hearing capabilities, little data are available regarding the physiologic performance of BAHSs in response to free-field sounds. METHODS Cochlear microphonics (CMs) were recorded from five chinchillas before and after destruction of one cochlea. A BAHS (Cochlear Baha) was fitted on the deafened side. CM measurements were made in response to tones, with and without the BAHS, to free-field sounds presented ipsilateral to the SSD, on the side of the normal ear, and along the midline. Stimuli were also presented directly through the BAHS and an earphone to generate sounds with interaural time and level differences approximating free-field sounds. RESULTS With the BAHS, CM thresholds were decreased (re: no BAHS) by approximately 10 dB for sources ipsilateral to the SSD, approximately 14 dB for midline sources, and approximately 5 dB for sources contralateral to the SSD. Changes in CM amplitudes and thresholds were sound location dependent. CM amplitudes were modulated by interaural time and level differences generated by the linear interaction of BAHS and acoustic signals. CONCLUSION This study suggests that BAHS can provide input to the normal ear that is modulated by sound location, which serves to reduce the head shadow effect and may also offer cues to sound location.

Mechanical stimulation through a cochlear third window into the scala tympani in a chinchilla model with normal and fixed stapes can generate cochlear responses equivalent to acoustic stimuli.Cochlear stimulation via the round window (RW) using active middle ear implants (AMEIs) can produce physiologic responses similar to acoustic stimulation including in a model of stapes fixation. However, pathologic conditions, such as advanced otosclerosis, can preclude delivery of sound energy to the cochlea through the oval window and/or the RW.Cochlear microphonic (CM) and laser Doppler vibrometer measurements of stapes and RW velocities were performed in 6 ears of 4 chinchillas. Baseline measurements to acoustic sinusoidal stimuli (0.25-8 kHz) were made. Measurements were repeated with an AMEI driving the RW or a third window to the scala tympani before and after stapes fixation.AMEI stimulation of the third window produced CM waveforms with morphologies similar to acoustic stimuli. CM thresholds with RW and third-window stimulation were frequency dependent but ranged from 0.25 to 10 and 0.5 to 40 mV, respectively. Stapes fixation, confirmed by laser Doppler vibrometer measurements, resulted in a significant frequency dependent impairment in CM thresholds up to 13 dB (at3 kHz) for RW stimulation and a nonsignificant frequency-dependent improvement of up to 10 dB (at3 kHz) via third-window stimulation.AMEI mechanical stimulation through a third window into the scala tympani produces physiologic responses nearly identical to acoustic stimulation including in a model of stapes fixation with decreased efficiency.

Objective To compare the speech understanding abilities of cochlear implant listeners using 2 microphone technologies, the Otologics fully implantable Carina and the Cochlear Freedom microphones. Study design Feasibility study using direct comparison of the 2 microphones, nonrandomized and nonblinded within case studies. Setting Tertiary referral center hospital outpatient clinic. Patients Four subjects with greater than 1 year of unilateral listening experience with the Freedom Cochlear Implant and a CNC word score higher than 40%. Intervention A Carina microphone coupled to a percutaneous plug was implanted on the ipsilateral side of the cochlear implant. Two months were allowed for healing before connecting to the Carina microphone. The percutaneous plug was connected to a body worn external processor with output leads inserted into the auxiliary port of the Freedom processor. Subjects were instructed to use each of the 2 microphones for half of their daily implant use. Main outcome measures Aided pure tone thresholds, consonant-nucleus-consonant (CNC), Bamford-Kowel-Bench Speech in Noise test (BKN-SIN), and Abbreviated Profile of Hearing Aid Benefit. Results All subjects had sound perceptions using both microphones. The loudness and quality of the sound was judged to be poorer with the Carina in the first 2 subjects. The latter 2 demonstrated essential equivalence in the second two listeners, with the exception of the Abbreviated Profile of Hearing Aid Benefit reporting greater percentage of problems for the Carina in the background noise situation for subject 0011-003PP. CNC word scores were better with the Freedom than the Carina in all 4 subjects. The latter 2 showed improved speech perception abilities with the Carina, compared with the first 2. The BKB-SIN showed consistently better results with the Freedom in noise. Conclusion Early observations indicate that it is potentially feasible to use the fully implanted Carina microphone with the Freedom Cochlear Implant. The authors would anticipate that outcomes would improve as more knowledge is gained in signal processing and with the fabrication of an integrated device.

After initial contact of the active middle ear implant (AMEI) on the incus, significant increases in device performance can be achieved intraoperatively without affecting residual hearing by additional static loading of the incus with 62 μm (quarter turn) to 125 μm (half turn) increments via an adjustment screw.To assess the performance gains of driving the incus with an AMEI under increasing static loads in cadaveric temporal bones.Incus drive efficacy was assessed using laser Doppler velocimetry measurements of stapes velocities over a frequency range of 0.25 to 8 kHz. Results were compared to stapes velocities following acoustic stimulation via insert earphone. Maximum equivalent ear canal sound pressure level (L(Emax)) and residual hearing loss after initial loading of the AMEI (first contact) were compared in each temporal bone. Additional increases in incus load were induced by turning an adjustment screw in quarter turn steps, corresponding to 62 μm increments per step. L(Emax)and residual hearing loss were reassessed after each step. For each temporal bone, experiments were repeated for three different AMEIs.On average across bones, incus stimulation upon initial contact produced an L(Emax)of 125, 127, and 121 dB SPL and residual hearing losses of -2, -1, and -1 dB with respect to unloaded, unaided conditions for the three AMEIs, respectively. Across bones and transducers, increasing static transducer load by incrementing the AMEI up to 125 μm significantly improved performance without affecting residual hearing loss. Loading beyond 125 μm (half turn) did not improve performance but significantly increased residual hearing loss.

HYPOTHESIS: Mechanical stimulation of the round window (RW) with an active middle ear implant (AMEI) with and without experimentally induced stapes fixation (SF) results in equivalent electrophysiologic measures of cochlear microphonic (CM), compound action potential (CAP), and auditory brainstem response (ABR). BACKGROUND: Where normal oval window functionality is mitigated, the RW provides a pathway to mechanically stimulate the inner ear. METHODS: Measurements of the CM, CAP, and ABR were made in 5 ears of 4 chinchillas with acoustic stimulation and with application of the AMEI to the RW with and without experimentally induced SF using pure-tone stimuli (0.25-20 kHz) presented at differing intensities (-20 to 80 dB SPL vs. 0.01 mV to 3.16 V). RESULTS: Morphologies of the CM, CAP, and ABR were similar between acoustic and RW stimulation with and without SF. Stapes fixation increased CM thresholds relative to RW stimulation without fixation by a frequency-dependent 4- to 13-dB mV (mean, 7.9 +/- 3.2 dB mV). Although the thresholds changed with SF, CM sensitivities and amplitude dynamic range were identical to normal. The CAP in all conditions demonstrated equivalent decreasing amplitudes and increasing latency with decreasing intensity (decibel sound pressure level versus decibel millivolt). Stapes fixation increased the CAP thresholds at all frequencies, ranging from 9 to 24 dB mV (mean, 17.7 +/- 4.9 dB mV). Auditory brainstem response waveforms were preserved across experimental conditions. CONCLUSION: Mechanical stimulation of the RW in an animal model of SF generates functionally similar inputs to the cochlea as normal acoustic and RW mechanical inputs but with increased thresholds. With further study, AMEIs may provide a surgical option for correction of otosclerosis and ossicular chain disruption.

Objectives The safety of the Otologics Fully-Implantable MET Ossicular Stimulator was assessed in adult patients with bilateral moderate to severe sensorineural hearing loss. Methods Surgical implantation of the ossicular stimulator was performed. A repeated-measure, within-subjects design assessed safety and aided sound field thresholds and speech performances with the subject’s own, appropriately fitted, walk-in hearing aid(s) and the Otologics Fully-Implantable MET Ossicular Stimulator. Results Twenty patients were implanted and activated as part of the Phase I clinical trial. Results demonstrated 10-20 dB of functional gain across audiometric frequencies. Pure tone averages and monaural word recognition scores were slightly better for the walk-in−aided condition, while patient benefit scales favored the postoperative implant-aided conditions. Conclusion/Significance Although monaural word scores and aided thresholds favored the walk-in−aided condition, preliminary results indicate that the Otologics MET Fully-Implantable Ossicular Stimulator is an alternative to currently available hearing aids in patients with sensorineural hearing loss.

HYPOTHESIS The goal of this study was to measure the tissue vibration amplitude that would be associated with an implantable microphone. BACKGROUND Totally implantable hearing devices have been desired by the hard-of-hearing community for some time. However, an implanted microphone must pick up desired acoustic signals in the presence of undesired signals, including vibration. To design an effective microphone, the level of tissue vibrations originating from anatomical sources and the implanted transducer must be understood. METHODS Using a laser Doppler vibrometer and an accelerometer, tissue vibrations were measured under the following conditions: (1) Normal control subjects during vocalization (n=4); (2) Vocalization and biological sounds measured on cranium and in soft tissue on normal subjects (n=6); (3) Transducer vibration measured on Otologics semi-implantable hearing device wearer (n=1) and human cadavers (n=4 ears). RESULTS Anatomical noise vibrations are 20 to 25 dB greater in soft tissue for frequencies less than 1,000 Hz than on the cranium, whereas vibrations due to implanted transducers are 20 to 25 dB greater on the cranium than in soft tissue inferior to the mastoid. Chewing vibrations are 10 to 15 dB greater than vocalization on the mastoid. Mastoid vibration levels measured in patients are equivalent to those in cadavers. Vibration levels do not vary significantly with respect to location on the cranium next to the pinna. CONCLUSION The greatest anatomical vibrations that an implanted microphone must overcome are because of vocalization in the soft tissue inferior to the mastoid and chewing vibrations on the mastoid. A human cadaver is an appropriate model for transducer cranial vibration studies. If the implantable microphone is placed on the cranium near the pinna, it makes little difference with regard to actual location.

Chronic otitis media was previously a contraindication to cochlear implantation. In recent years, potential benefits of implantation in deaf children with chronic suppurative otitis media has fueled new approaches to this treatment dilemma. We review the current and historical literature, analyze the risk and benefits, and perioperative treatments and operative techniques to improve outcomes and minimize complications of cochlear implantation in children with chronic suppurative otitis media. We conclude that cochlear implantation in children with chronic suppurative otitis media is a viable therapy if adequate and meticulous preoperative and perioperative management is undertaken.

Cavernous hemangiomas are rare lesions that may be difficult to distinguish from acoustic neuromas, schwannomas, or other lesions of the cerebellopontine angle on imaging studies. The clinical history, workup including radiologic evaluation, histologic assessment, and a brief review of the literature are presented.

This study was conducted to demonstrate the safety and efficacy of the Otologics Middle Ear Transducer (MET) Ossicular Stimulator and, in particular, to compare the audiologic benefits of this novel form of electromechanical stimulation with those of conventional acoustical amplification.A total of 282 patients were implanted with the device in Europe and the USA. Pure-tone audiometry, speech recognition and subjective assessment of benefit were tested before the surgery and 2, 3, 6 and 12 months afterwards. The US patients were fitted with a digital hearing aid for a minimum of 4 weeks prior to surgery, and the same benefit measures were performed with the digital hearing aid and their "walk-in" hearing aid.Group mean postoperative bone and air conduction thresholds did not change significantly from preoperative levels. Postoperative air conduction thresholds decreased slightly in some individual patients, due to the mass loading effect exerted by the transducer on the ossicles. Sufficient gain was available to reach target prescription levels for moderate to severely impaired hearing individuals. Speech and subjective assessment of patient preference indicated that patients did as well or better with the MET Ossicular Stimulator than with their "walk-in" aid or the standardized digital aid.The capability of the MET Ossicular Stimulator to provide appropriate gain as a function of degree of hearing loss indicates that the device is a viable treatment for moderate to severe sensorineural hearing loss in adults.

Objectives/Hypothesis: Delayed-onset facial paralysis (beginning more than 3 d after the procedure) has been described as a complication of many different types of otological procedures. The incidence of this problem in vestibular neurectomy and the relationship to surgical approach are detailed in the study. Study Design: Retrospective case review. Methods: In the setting of a tertiary referral center, vestibular neurectomy was performed in 70 individuals with disabling vertigo unresponsive to medical therapy who elected vestibular neurectomy. The main outcome measure was incidence of delayed onset facial paralysis. Results: Delayed-onset facial paralysis was significantly more common after the middle fossa (18%) and translabyrinthine (11%) approaches compared with the retrosigmoid approach (0%) Conclusions: Surgical approach influences the incidence of delayed-onset facial paralysis. Measures to prevent this complication such as prophylactic antiviral medication or labyrinthine segment decompression may be considered in middle fossa and translabyrinthine operations.

Physiology and Biophysics Departments, University of Colorado School of Medicine,Aurora, Colorado, U.S.A.Hypothesis: Active middle ear implant (AMEI) generatedvibromechanical stimulation of the ossicular chain (ossicularchain vibroplasty [OCV]) or the round window (round windowvibroplasty [RWV]) is not significantly affected by simulatedmiddle ear effusion in a human temporal bone model.Background: OCV and RWV may be employed for sensori-neural, mixed, and conductive hearing losses. Although middleeareffusionsmaybeencounteredacrosspatientpopulations,littleisknownabouthoweffusionsmayaffectAMEIvibromechanicalefficiency.Methods: Laser Doppler vibrometry of stapes velocities (SVs)were performed in a human temporal bone model of simulatedeffusion (N = 5). Baseline measurements to acoustic sinusoidalstimuli, OCV, and RWV (0.25Y8 kHz) were made without ef-fusion. The measurements were repeated with simulated middleear effusion and compared with baseline measurements. Datawere analyzed across 3 frequency bands: low (0.25Y1 kHz),medium (1Y3 kHz), and high (3Y8 kHz).Results: Acousticstimulation withsimulated middle ear effusionresulted in a significant (p G0.001) frequency-dependent atten-uation of SVs of 4, 10, and 7 dB (low, medium, and high ranges,respectively). OCV in simulated effusion resulted in attenuatedSVs of 1, 5, and 14 dB (low, medium, and high) compared towithout effusion; however, this attenuation was not significant(p = 0.07). Interestingly, in the setting of RWV, simulated effu-sion resultedinsignificantly(p =0.001)increased SVsof16,11,and 8 dB (low, medium, and high). A 3-dB variance in AMEIefficiency was observed in repeated measurements in a singletemporal bone.Conclusion: The efficiency of OCV was not significantly af-fected by the presence of a middle ear effusion. Improved effi-ciency, however, was observed with RWV. Key Words: Activemiddle ear implantVLaser Doppler vibrometryVMiddle eareffusionVTemporal bone.Otol Neurotol 35:470Y475, 2014.

Hypothesis: Coupling and placement of actuators onto the ossicular chain have a significant influence on active middle ear implant (AMEI) performance. Background: AMEIs have proved to be effective in treating moderate-to-severe sensorineural hearing loss as well as mixed and conductive loss. Here, we assess the effect on performance of an AMEI prosthesis using 5 different methods of coupling to the ossicular chain in 6 temporal bones. Methods: The AMEI provided direct vibratory stimuli to the incus using the following methods: 1) tip of the transducer in contact with incus body (baseline condition), 2) tip of the transducer placed in a laser-drilled hole in the incus body, 3) the aWengen clips (straight and articulated) crimped to the transducer and attached to the incus long process, 4) a 0.5-mm diameter cylinder placed in contact with the incus long process, and 5) a bell-shaped prosthesis in contact with the head of the stapes. Performance in each condition was assessed by measuring the resultant stapes velocities (HEV) from which the maximum equivalent ear canal sound pressure levels (LEmax) were computed. Results: Relative to the baseline condition, which produced LEmax of 112 to 126 dB SPL for frequencies of 0.25 to 8 kHz, the other coupling methods produced similar or substantially improved (increased LEmax) performance. Best performance was achieved by providing vibratory stimulation to the head of the stapes directly with the bell-shaped tip where performance improved significantly by 16 to 22 dB. Conclusion: Stapes velocities produced by AMEI transducers may be increased depending on the tip used to couple the transducer to the ossicular chain and the placement of the stimulating tip along the incus. Improvement in coupling the transducer to the incus and stapes produced significant improvements in the transfer of vibratory stimuli to the ossicular chain.

To study the effects of various active middle ear implant loading parameters on round window stimulation in an animal model.Physiological measurements of the cochlear microphonic and stapes velocity were made from active middle ear implant-generated sinusoidal stimuli with controlled changes in loading parameters.Prospective study at an academic research institution.Cochlear microphonic and stapes velocities (H(EV)) were measured in 6 study subjects (Chinchilla lanigera) in response to active middle ear implant (Otologics MET, Boulder, Colorado) round window stimulation with assessment of effects of varying parameters of loading pressure, interposed connective tissue, and angle of stimulation with respect to the round window membrane.The measured performance variabilities in repeated applications of the active middle ear implant to the round window were 2.5 dB and 5.0 dB for H(EV) and cochlear microphonic thresholds, respectively. Loading pressure applied to the round window (51-574 dynes) and angle of approach (±30° with respect to coronal plane) did not have a significant effect on cochlear microphonic thresholds or H(EV). Significant improvements in cochlear microphonic thresholds and H(EV) were observed for interposed connective tissue regardless of tissue type.Variability in performance due to repeated couplings of the active middle ear implant to the round window is small and reproducible. Interposition of connective tissue significantly improves vibration energy transfer to the cochlea. Neither changes in loading pressure nor angle of stimulation of the round window affected active middle ear implant performance.

HYPOTHESIS Driving the oval window directly with an active middle ear implant (AMEI) can produce high levels of input to the inner ear. BACKGROUND Treatment of otosclerosis bypasses the stapes with a piston that penetrates the vestibule. Although this treats the conductive component of hearing loss, it does not treat the sensorineural part, which can be improved using an additional conventional hearing aid. Active middle ear implants have been proposed to be an alternative in treating otosclerosis in cases of mixed hearing losses. METHODS Seven temporal bones were prepared to expose the stapes and round window (RW). Stapes and RW velocities were measured while driving with an AMEI the stapes head with a bell-shaped tip. The stapes footplate was then fixed with acrylic cement; fixation was confirmed through attenuated RW velocities. A cylinder tip (0.5 mm) was then used to drive the inner ear through a stapedotomy with and without interposition of fascia. RESULTS Driving the stapes with an AMEI produced mean maximum equivalent ear canal sound pressure levels (SPL) of 138 dB (0.25-8 kHz at 1 V [RMS]). Stapes fixation caused a approximately 25-dB attenuation. Driving with a cylinder tip through the stapedotomy produced 114 dB SPL (24 dB less than normal) and 110 dB SPL (28 dB less than normal) performance with and without fascia, respectively. Performance with fascia was greater than without. CONCLUSION Driving the oval window with an AMEI in a scenario of stapes fixation was demonstrated to be feasible, with performance comparable to traditional AMEI coupling to the incus or stapes. These possibilities offer new perspectives to treat mixed hearing loss in case of fixed footplate.

• The temporal bone histopathologic findings of a patient having received a Nucleus 22-channel cochlear implant (Cochlear Corp, Englewood, Colo) following bilateral transverse otic capsule fractures is presented. The case was complicated by perilymph fistulas, labyrinthitis, meningitis, and death due to drowning. The left cochlea revealed complete labyrinthitis ossificans; the implanted right cochlea demonstrated new bone formation in the basal turn of the scala tympani, degeneration of the organ of Corti, but normal ganglion cell counts. Results of psychophysical and speech perception 4 months after implantation are presented. ( Arch Otolaryngol Head Neck Surg. 1992;118:1257-1265)

Objective: The goal was to measure quality of life (QOL) and hearing-specific functional status before and after treatment of conductive hearing loss (CHL). Study Design and Setting: A prospective, longitudinal, outcomes-based study was performed at an academic medical center. Results: Mean baseline QOL scores in CHL patients were comparable with those of the general population. Audiometric studies indicated significant improvements in hearing threshold in all treated patients. There was no significant improvement in mean global QOL scores after treatment of CHL, although there was little room for improvement over baseline. The hearing-specific instrument did demonstrate significant improvements in emotional and social/situational hearing status after treatment. Patients treated with hearing aids had poorer baseline QOL and hearing status than patients treated with surgery and tended to show declines in QOL and only partial improvement in hearing-specific functional status after treatment. Conclusions: Treatment of CHL resulted in improvements in hearing-specific functional status, although changes were difficult to detect with a global QOL instrument. (Otolaryngol Head Neck Surg 2000;123:527-3.)

Balance disorders in elderly patients are associated with an increased risk of falls but are often difficult to diagnose because of comorbid chronic medical problems. We performed a cross-sectional study to determine the prevalence of unrecognized benign paroxysmal positional vertigo (BPPV) and associated lifestyle sequelae in a public, inner-city geriatric population. Dizziness was found in 61% of patients, whereas balance disorders were found in 77% of patients. Nine percent were found to have unrecognized BPPV. Multivariate analysis demonstrated that the presence of a spinning sensation and the absence of a lightheadedness sensation predicted the presence of unrecognized BPPV. Patients with unrecognized BPPV were more likely to have reduced activities of daily living scores, to have sustained a fall in the previous 3 months, and to have depression. These data indicate that unrecognized BPPV is common within the elderly population and has associated morbidity. Further prospective studies are warranted.

The sensory hair cells of the inner ear are responsible for converting balance and hearing stimuli into electrical signals. Until recently, all previous studies of hair cell physiology had been performed on tissue obtained from non-mammals and rodents. In primates, hair cells are difficult to access, because they rest within the densest structure of the body, the otic capsule of the temporal bone. In this report, we describe a technique that we have used in physiological studies to harvest living human hair cells. We collected vestibular and cochlear tissue specimens from adult humans undergoing translabyrinthine and transotic surgical approaches for resection of lateral skull base tumors. Viable hair cells were identified and visualized with light microscopy. The ability to study normal hair cells from humans may further the study of normal and pathological human sensation, hair cell regeneration, and genetic causes of balance and hearing disorders.

Transverse fractures often violate the otic capsule and commonly, although not invariably, result in immediate and profound sensorineural hearing loss. The pathogenic mechanisms producing sensorineural hearing loss include direct trauma to the cochlear nerve, disruption of the membranous labyrinth, vascular compromise or hemorrhage into the inner ear, perilymphatic fistula, and endolymphatic hydrops. The last two mechanisms account for the occasional patient who develops progressive sensorineural hearing loss after the initial insult. On early posttraumatic evaluation three patients were discovered to have transverse fractures and residual auditory function. Deterioration of hearing led to middle-ear exploration with closure of perilymphatic fistulas. Hearing was preserved in two patients. Diagnosis of posttraumatic perilymphatic fistulas requires early audiometric assessment, high-resolution computed tomographic scanning of the temporal bones to detect fracture of the otic capsule and pneumolabyrinth, and a high index of clinical suspicion. (Arch Otolaryngol Head Neck Surg. 1995;121:795-799)

Background: Pure tones stimulated oscillopsia in a 30-year-old man with bilateral hearing loss and Tullio's phenomenon. Design: The subject's eye movements were recorded with electro-oculography while he was seated with his head stabilized facing a visual array. Pure tones were given in each ear, individually, from 500 to 2000 Hz, 90 to 110 dB. The subject reported the intensity of oscillopsia, if any, during each trial. He was also tested while standing on a force platform and receiving pure tones. Results: No increased postural sway was found, but oscillopsia and vertical eye movements followed stimulation to the more impaired ear. Conclusions: These results support the hypothesis that Tullio's phenomenon is caused by inner ear pathology and suggest that oscillopsia is caused by the occurrence of unplanned vertical eye movements, the perceptual consequences of which were unexpected. (Arch Otolaryngol Head Neck Surg. 1995;121:459-462)

Temporal bone fractures often cause loss of audiovestibular function. Those patients with bilateral profound sensorineural hearing losses secondary to temporal bone fractures become candidates for cochlear implantation. The authors present the histopathology of five temporal bone fractures in three patients, evaluating specifically the traumatic effects on the neural elements of the inner ear. Transverse fractures of the temporal bone result in severe loss of hair cells, ganglion cells, and other supporting cells in the inner ear. Occasionally labyrinthitis ossificans may occur as a consequence of trauma or infection. While longitudinal fractures do not violate the otic capsule, these same neural elements may be damaged by concussion.

With advances in imaging, intracanalicular acoustic neuromas are identified readily in patients including, oftentimes, those with serviceable hearing. Fourteen patients were operated on in an attempt to preserve hearing. Hearing was retained in 10 (71%) of the 14. Serviceable hearing was present in 7 (50%), borderline serviceable hearing in 2 (14%), and nonserviceable hearing in 1 (7%). The problems, advantages, and disadvantages of the differing approaches are discussed.

Lateral surgical approaches to the base of the skull through the temporal bone often result in a large cavity with exposed dura and vascular structures and no possibility of reconstruction of the middle ear conductive hearing mechanism. Subtotal petrosectomy with tympanomastoid obliteration provides a relatively safe and secure closure of the surgical defect in the temporal bone and eliminates the problems associated with an open mastoid cavity. Eradication of all accessible air cell tracts and mucosa in the petrous pyramid, obliteration of the eustachian tubal orifice, closure of the external auditory canal, and fat obliteration of the middle ear and mastoid clefts are essential in the procedure. Over the last 10 years this technique has been utilized in 372 base of skull procedures with a complication rate of less than 5%. Infection occurred only in those cases with draining cavities or contaminated wounds.

• Since a previous study conducted at the Ear, Nose, and Throat Department, University Hospital, in Zurich, Switzerland, 16 additional cases of glomus jugulare of the temporal region have been evaluated and treated surgically in this department. This article describes our experience with these additional cases and gives an in-depth description of the surgical techniques that are used in the treatment of more complicated tumors. We report one case in detail. ( Arch Otolaryngol 1981;107:209-214)

Primary tumors of the facial nerve are relatively rare and have a variety of presenting symptoms. This article reviews 248 cases of facial neuroma in the world's literature and adds seven cases that were managed at the Baylor College of Medicine. Facial weakness was most common symptom, with facial spasm or tics, hearing loss, and masses in the external auditory canal also being frequently seen. At surgery, the tympanic, vertical, and labyrinthine segments were the most commonly involved areas. On the basis of this review, general principles have been drawn up to help the clinician in diagnosis and management of this (at times) difficult problem.

Pathologic changes in the temporal bone are described in a case of polyarteritis nodosa in a 48 year old man in whom the onset of sudden unilateral deafness and vertigo occurred seven months prior to death as one of the early manifestations of the disease. The patient had received only a seven week course of prednisolone and, earlier, a two week course of anti-inflammatory agents. Autopsy revealed involvement of the arteries supplying the kidneys, testes, and pancreas. Changes within the temporal bone were seen bilaterally and there was thickening of the mucosa of the middle ear. Inner ear involvement was mainly limited to the cochlea, the deaf ear showing more pronounced changes. These changes included loss of the organ of Corti in the hook portion of the basal coil, absence of the tectorial membrane, and atrophy of the stria vascularis. The scala tympani was obliterated by fibrosis and new bone formation. The scala media showed hydrops, and a marked decrease in the spiral ganglion cells and nerve fibers supplying this portion of the cochlea was evident. Focal changes were seen throughout the remainder of the cochlea. The vestibular structures showed no detectable pathologic changes. Small vessel arteritis was found in the dural and subarcuate vessels in both temporal bones.

Quantitative analysis of electro-oculographic recordings of eye movement in response to precise visual and vestibular stimuli makes possible the differentiation of three categories of vestibular syndromes due to pathological changes in three different parts of the visual vestibulo-ocular reflex arc: (1) decreased vestibulo-ocular reflex gain (e.g., decrease in slow component velocity), but normal fast components and visual-vestibular interaction (labyrinth and eighth nerve); (2) normal slow component velocity but abnormal fast components to all stimuli (pontine or medullar reticular formation); and (3) normal slow component velocity to vestibulo-ocular stimulaton but abnormal visual-vestibular interaction as well as normal fast components (visual-motor pathways or cerebellum).

Epidermoids are blastomatous malformations of abnormal epithelial proliferation. Intradiploic epidermoids are very rare lesions that may occur in all flat bones of the calvarium and in the paranasal sinuses, maxilla, temporal bone, and sphenoid bone. This article describes the unique case of an intradiploic epidermoid tumor located in the greater sphenoid wing. Theories of pathogenesis, clinical behavior, diagnosis, and treatment of diploic epidermoids are reviewed.

• While auditory involvement in multiple sclerosis is not infrequent, sensorineural hearing loss as the initial manifestation of this disease is rare. Auditory brain-stem evoked responses, speech audiometry, acoustic reflexes, and electronystagmography yield significant objective information concerning brain-stem involvement. Magnetic resonance imaging objectively documents white matter demyelinization. The acute onset of the retrocochlear type of auditory dysfunction without other evidence of central nervous system involvement can be an early manifestation of this disease. Two patients with multiple sclerosis had sudden sensorineural hearing loss, with one patient experiencing this as the sole initial complaint. ( Arch Otolaryngol Head Neck Surg 1989;115:41-45)

The argon laser has been used clinically to perform stapedotomies in patients with otosclerosis. In order to determine if this device induces histologic changes in the inner ear, stapedotomies were performed in cats. Saccular membrane fistulas, in line with the path of the laser beam, were found in 3 of 8 ears. The unpredictable nature of the argon laser in the ear is discussed.

The vestibular and optokinetic ocular control systems were studied in 10 patients with cerebellar atrophy and in 10 normal subjects using (1) constant velocity optokinetic stimulation, (2) sinusoidal rotation in the dark, and (3) sinusoidal rotation in the light with a surrounding fixed optokinetic drum. The gain (maximum slow component velocity/maximum head or drum velocity) of induced nystagmus was calculated from electro-oculographic recordings. Optokinetic nystagmus was abnormal in seven patients and the average optokinetic gain in the patients was significantly (p less than 0.01) less than that of the normal group. Three patients with "clinically pure" cerebellar atrophy had increased vestibular responses, and one patient with clinical signs of peripheral neuropathy had decreased responses, probably due to associated vestibular nerve disease. The average vestibulo-ocular reflex gain in patients did not differ significantly from controls (p greater than 0.05). Three patients had normal vestibular and optokinetic responses when tested independently, but had abnormal visual-vestibular interaction. These patients probably had selective disorders of the midline cerebellar pathways that mediate visual-vestibular interaction. By studying each system, both independently and during interaction, all patients were identified as abnormal, and a more precise anatomic localization of the atrophy was obtained.

Suprathreshold morphologic characteristics of the acoustic stapedius reflex are reported for five subjects with acoustic tumor. Results support the hypothesis that changes in suprathreshold morphology may be more sensitive to acoustic tumor than conventional reflex threshold and decay measures. Both the afferent relative amplitude index (AI) and measures of sequential variability of individual waveforms appear to be especially promising.

• Autoimmune sensorineural hearing loss was first described in 1979. This may be secondary to a systemic autoimmune disease, or in some cases, to a direct autoimmune insult to the labyrinth. A case of active ulcerative colitis and progressive sensorineural hearing loss responded to corticosteroid therapy. ( Arch Otolaryngol 1984;110:810-812)

The potential usefulness of impedance studies is reviewed and a case of osteogenesis imperfecta, having bilateral ossicular discontinuity and intact acoustic reflexes, is presented. This seeming paradox was explainable on the basis of surgically confirmed, bilateral disruption of the stapes crura, central to the stapedial tendon insertion.

A series of 26 patients undergoing translabyrinthine acoustic neuroma surgery was evaluated pre- and postoperatively using rotatory vestibular testing. Patients were tested immediately prior to surgery and followed long-term at frequent intervals for periods of one week to two years, depending on availability and length of time postoperative. Rotatory testing was performed at multiple frequencies of 0.0125, 0.05, and 0.2 Hz, and the vestibulo-ocular reflex was measured using electro-oculographic techniques. Dependent variables of the slow component of the vestibulo-ocular reflex were derived by computer analysis, including gain, phase, DC bias, ampullopetal and ampullofugal responses of the remaining labyrinth, and asymmetry. These variables changed in a predictable fashion as related to the reciprocal of time. Results of this data are fitted with a linear statistical model, validating the changes.

Individual speech tracking data were analyzed in relation to other variables in 11 adult users of the Nucleus multichannel cochlear implant. Patients were categorized according to postoperative speech tracking results. The resultant groups could also be differentiated on the basis of postoperative MAC scores, surgeon's rating of overall success, and duration of deafness before implantation. The speech tracking paradigm appears to be a useful technique for the evaluation of performance with a cochlear prosthesis.

• A mother and daughter both presented at age 5 years with the triad of right-sided congenital cholesteatoma, right preauricular pits, and bilateral sensorineural hearing loss. Twenty-six years apart, both were treated with middle ear exploration and removal of a cholesteatoma that filled the sinus tympani, facial recess, and middle ear. The sensorineural hearing losses were nonprogressive, and the preauricular pits were asymptomatic. These two cases may represent a unique variant of branchio-oto dysplasia. The mechanism of formation of these anomalies and the possible modes of inheritance are conjectural. This triad, however, supports genetic predisposition rather than aberrant epithelial rests during morphogenesis as a possible cause in congenital cholesteatoma. ( Arch Otolaryngol Head Neck Surg 1986;112:1097-1100)

We evaluated the role of the vestibulocerebellum in the production of visual-vestibular-oculomotor reflexes in rabbits. Oculomotor responses (nystagmus) were compared with optokinetic, vestibular, and combined visual-vestibular stimuli, obtained before and after bilateral removal of the flocculus, paraflocculus, and paramedian lobes. Measurements were made in response to binocular and monocular stimulation. These experiments give further evidence that, in the rabbit, each eye is mainly connected to the ipsilateral vestibular floccular structures and corroborate previous investigations that point to the significance of the vestibulocerebellum in the optokinetic and visual-vestibular-ocular reflexes.

Meningiomas are the most common benign intracranial neoplasms, and although the otolaryngologist rarely sees these lesions, he or she may encounter them in surgery of the skull base. Surgical removal is the primary treatment modality for these meningiomas. To avoid recurrent disease, the best initial therapy is the most extensive procedure that can reasonably be effected. Chemotherapy and irradiation therapy have, at best, only limited roles in treatment.