Sound localization measured by eye-tracking.

OBJECTIVE: To introduce a new method of measuring sound localization ability based on eye-tracking and to test this method by analysing the influence of mild induced conductive hearing loss on sound localization. DESIGN: Sound signals were presented from different angles, and the participant's responses were measured using an eye-tracking device. For validation, a comparison of responses to visual stimuli was performed. To test the clinical application of this method, a mild conductive hearing loss was simulated, and the impact of this change on sound localization was measured. STUDY SAMPLE: Fifteen participants. RESULTS: The system provided repeatable measurements, and there was a good correlation of sound and visual signals. A large number of trials could be completed fairly rapidly. Following the induced conductive hearing loss, a decline of 5.5° in the accuracy of sound localization in the horizontal plane was found towards the side of the non-impaired ear for frontal presentations. CONCLUSIONS: Quantifying sound localization by eye-tracking was found to be feasible, fast and accurate. A mild conductive hearing loss caused a slight degradation of sound localization accuracy within the 30° frontal sector, which is in good agreement with results found using methods requiring more extensive instrumentation.

Auditory Cortical Plasticity in Patients with Single-Sided Deafness Before and After Cochlear Implantation.

PURPOSE: This study investigated neuroplastic changes induced by postlingual single-sided deafness (SSD) and the effects of a cochlear implantation for the deaf ear. Neural processing of acoustic signals from the normal hearing ear to the brain was studied before and after implantation using a positron emission tomography (PET)/CT scanner. METHODS: Eight patients with postlingual SSD received a cochlear implant (CI) in a prospective clinical trial. Dynamic imaging was performed in a PET/CT scanner using radioactively labeled water ([15O]H2O) to localize changes in the regional cerebral blood flow (rCBF) with and without an auditory task of logatomes containing speech-like elements without meaningful context. The normal hearing ear was stimulated before implantation and after the use of the cochlear implant for at least 8 months (mean 13.5, range 8.1-26.6). Eight age- and gender-matched subjects with normal hearing on both sides served as healthy control subjects (HCS). RESULTS: When the normal hearing ear of SSD patients was stimulated before CI implantation, the [15O]H2O-PET showed a more symmetrical rCBF in the auditory regions of both hemispheres in comparison to the HCS. The use of CI increased the asymmetry index (AI) in six of eight patients indicating an increase of activity of the contralateral hemisphere. Non-parametric statistics revealed a significant difference in the AI between patients before CI implantation and HCS (p < .01), which disappeared after CI implantation (p = .195). CONCLUSION: The functional neuroimaging data showed a tendency towards normalization of neuronal activity after CI implantation, which supports the effectiveness of CI in SSD patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01749592, December 13, 2012.

Generation of distortion product otoacoustic emissions in infants with a combined air and bone conduction stimulus.

OBJECTIVES: Evaluation of Distortion Product Otoacoustic Emissions (DPOAEs) by combining Air Conduction (AC) and Bone Conduction (BC) stimuli in infants. METHODS: Measurements were performed in 19 normal hearing infants, and in 23 adults serving as a control group. The stimulus consisted either of two AC tones, or of combined AC/BC tones. DPOAEs were measured for f2 at 0.7, 1, 2, 4 kHz, and a constant ratio of f2/f1 = 1.22. Sound pressure level of the primary stimulus L1 was held constant at 70 dB SPL, while the level of L2 was decreased in 10 dB steps from 70 to 40 dB SPL. A response was included for further analysis when DPOAEs reached a Signal to Noise Ratio (SNR) of ≥6 dB. Additional DPOAE responses of <6 dB SNR were included when visual inspection of the measurements indicated clear DPOAEs. RESULTS: DPOAEs could be elicited in infants at 2 and 4 kHz for the AC/BC stimulus. DPOAE amplitudes evoked by the AC/AC stimulus were larger than those by the AC/BC stimulus, with the exception of 1 kHz. The highest amplitudes of DPOAEs were registered for a stimulation level of L1 = L2 = 70 dB, with the exception of AC/AC at 1 kHz, where the highest amplitudes were with L1-L2 = 10 dB. CONCLUSIONS: We demonstrated that DPOAEs can be generated in infants by a combined AC/BC stimulus at 2 and 4 kHz. The high noise floor needs to be further reduced to achieve more valid measurements in frequencies <2 kHz.

Neuromuscular choristoma of the internal auditory meatus.

Choristomas of the internal auditory meatus are exceedingly rare tumors. In most cases, neuromuscular choristomas have initially been misdiagnosed as vestibular schwannomas (VS). No known characteristics in the clinical presentation or in imaging exist distinguishing these tumors from VS, which are the most common tumors at this location [Smith et al.: AJNR Am J Neuroradiol 1997;18:327-329]. We present a case of a neuromuscular choristoma of the 8th cranial nerve that was operated because of growth demonstrated on two MRI scans 3 months apart. We were convinced that this young patient would require treatment sometime in the future, and we believed that an operation at that time had higher chances to preserve the anatomical structures. Histomorphological examination of the tumor revealed a nodular lesion with fascicular and nodular assembled smooth muscle cells, connective tissue and nerve fibers.

Gender and hearing aids: patterns of use and determinants of nonregular use.

OBJECTIVE: Research addressing gender and hearing has focused mainly on differences in the auditory systems of men and women, communication, and psychological issues. Differences between men and women in the use of hearing aids are less clear. To date, no study has examined the effects of gender on hearing aid use as a primary aim. However, use patterns and underlying reasons for not using hearing aids may differ between men and women, or there might be a gender difference in the impact of some determinants on hearing aid use. A consideration of such factors could increase hearing aid use. Therefore, the aim of the present investigation was to provide information about gender-related influences on hearing aid use by examining differences in usage patterns and determinants of nonregular use. DESIGN: This study used cross-sectional survey data from 4979 adult male and 3410 adult female hearing aid owners in Switzerland in 2005. The survey data, including self-reported hearing aid use, were matched to the hearing loss data and the hearing aid technical information. Descriptive analyses were performed for the use patterns, age at first fitting, and audiogram slope. The determinants of nonregular use were examined using logistic regression models that were stratified by gender. RESULTS: Compared with men, women reported a higher prevalence of daily and regular use and a longer daily duration of use of hearing aids. Men more commonly indicated a limited benefit as a reason for nonregular use. The multivariate analyses showed that nonregular use was significantly less likely in women. The audiogram slope strongly contributed to this difference. Stratified analyses showed that for both men and women, poor handling and low satisfaction were associated with a higher likelihood for nonregular hearing aid use. Associations were discrepant for asymmetric hearing loss, which was a risk factor in women but a protective factor in men. Higher risks of nonregular use were found in men with steeper audiogram slopes and longer durations of ownership of their current aids, in women fitted with their first aid in the previous 2 to 5 yr, and in women older than 65 yr. CONCLUSIONS: Overall, the present study provides evidence of gender-specific factors that influence hearing aid use patterns in men and women and of groups at higher risk for nonregular hearing aid use. Men with steeper audiogram slopes and the other subgroups of men and women with an increased risk for nonregular use should given particular attention when fitting their aids. As common risk factors for nonregular use, poor handling and low satisfaction should be addressed during the fitting process for all users. Further research is needed to clarify the differential influence of asymmetric hearing loss on hearing aid use in men and women. This information could improve hearing aid use and should be incorporated into daily clinical practice.

Prevalence of age-related hearing loss in Europe: a review.

Populations are becoming progressively older thus presenting symptoms of diminished organ function due to degenerative processes. These may be physiological or caused by additional factors damaging the organ. Presbyacusis refers to the physiological age-related changes of the peripheral and central auditory system leading to hearing impairment and difficulty understanding spoken language. In contrast to epidemiological data of other continents, the prevalence of age-related hearing loss (ARHL) in Europe is not well defined, due in part to the use of different classification systems. We performed a systematic literature review with the aim of gaining a picture of the prevalence of ARHL in Europe. The review included only population and epidemiological studies in English since 1970 with samples in European countries with subjects aged 60 years and above. Nineteen studies met our selection criteria and additional five studies reported self-reported hearing impairment. When these data were crudely averaged and interpolated, roughly 30% of men and 20% of women in Europe were found to have a hearing loss of 30 dB HL or more by age 70 years, and 55% of men and 45% of women by age 80 years. Apparent problems in comparing the available data were the heterogeneity of measures and cut-offs for grades of hearing impairment. Our systematic review of epidemiological data revealed more information gaps than information that would allow gaining a meaningful picture of prevalence of ARHL. The need for standardized procedures when collecting and reporting epidemiological data on hearing loss has become evident. Development of hearing loss over time in conjunction with the increase in life expectancy is a major factor determining strategies of detection and correction of ARHL. Thus, we recommend using the WHO classification of hearing loss strictly and including standard audiometric measures in population-based health surveys.

ADHEAR device in bone conduction audiometry.

ADHEAR is a bone conduction hearing aid that uses an adhesive skin adapter. In the current study, the use of ADHEAR as an audiometric bone stimulator was investigated in normal-hearing subjects by comparing it to the standard Radio-Ear B71. Bone conduction thresholds of 15 normal-hearing subjects (aged 21-36 years) were measured four times in a randomized order, twice with the B71 and twice with the ADHEAR. There were no significant differences in test-retest reliability between the two devices. Subjectively rated comfort was better for the ADHEAR. The development of a specific audiometric adhesive bone stimulator may be warranted.

Conductive Hearing Loss with Age-A Histologic and Audiometric Evaluation.

A retrospective analysis to quantify age-related changes of the incudo-malleolar joint (IMJ) and incudo-stapedial joint (ISJ), and to analyse changes in the air-bone gap (ABG) with age, was performed. Defined histologic parameters of 153 IMJ and 106 ISJ from subjects aged from birth to 70 years were correlated to age. Additionally, audiograms of 1760 ears of 974 other subjects aged 20 to 80 years were retrospectively analysed and the ABG was correlated to age. The joint space (age group from 0 to 10 compared to 61 to 70 years) became significantly wider with age (IMJ: from a mean of 44 µm to 100 µm, p < 0.001; ISJ: from a mean of 28 µm to 69 µm, p < 0.009. The thickness of cartilage of the incus decreased in the first 20 years of life (IMJ, from a mean of 88 µm to 65 µm, p < 0.01; ISJ: from a mean of 44 µm to 35 µm, p < 0.01). The ABGs of younger ears (20-40 years) was significantly larger at 500 Hz compared to older ears (60-80 years) by 2-4 dB, while it was significantly smaller by 3-5 dB at 4000 Hz (p < 0.0017). Interindividual variations in all age groups were large for both analyses. The increased joint spaces could potentially reduce the stiffness in the joints and explain the increase in ABG at 4000 Hz and the drop at 500 Hz. While the average change is small and of minimal clinical relevance, a larger increase of ABG with age is seen in some subjects.

Magnet displacement: a rare complication following cochlear implantation.

The purpose of this paper is to describe cases which reported complication after cochlear implantation in children: displacement of magnet from the receiver pocket, possibly aided by the use of magnetic toys. We observed magnet displacement in two female children from the same family and in one male child. Age at implantation was 23, 51, and 24 months, respectively. Magnet displacement occurred at 37, 16, and 32 months, respectively after the initial surgery. The magnets were replaced under general anaesthesia and we did not observe recurrent magnet dislodgement. Measurements indicated that forces required to remove the magnet from its pocket were not greater than those exerted by magnetic toys or the magnet used in the external sender coil. Although magnet displacement is not common after cochlear implantation, it is a major complication in children where subsequent general anaesthesia and surgery are necessary to replace the magnet. Therefore, we propose that pockets for removable magnets of cochlear implants used in children should be redesigned to increase forces to remove the magnet or that removable magnets not be used at all.

Survey on hearing aid outcome in Switzerland: associations with type of fitting (bilateral/unilateral), level of hearing aid signal processing, and hearing loss.

The present investigation further analysed results of a previously reported survey with a large sample of hearing aid owners (Bertoli et al, 2009) to determine the individual and technological factors related to hearing aid outcome. In particular the associations of hearing loss, level of signal processing, and fitting type (bilateral versus unilateral fitting) with hearing aid use, satisfaction with and management of the aid were evaluated. A sub-group with symmetrical hearing loss was analysed (n = 6027). Regular use was more frequent in bilateral users and in owners of devices with more complex signal processing, but the strongest determinant of regular use was severity of hearing loss. Satisfaction was higher in the group wearing simple devices, while fitting type and degree of hearing loss had no influence on satisfaction rates. Moderate and severe hearing loss was associated more frequently with poor management of the aid than mild hearing loss. It was concluded that bilateral amplification and advanced signal processing features may contribute to successful hearing aid fitting, but the resulting differences must be considered to be relatively small.

Survey on hearing aid use and satisfaction in Switzerland and their determinants.

The purpose of this study was to investigate the efficiency of the Swiss hearing aid dispensing system, and to determine factors contributing to successful hearing aid provision. A national cross sectional survey was performed using a postal questionnaire with 8707 adult hearing aid owners (response rate 62%). To correct results for a potential non-response bias, 193 randomly selected non-respondents were contacted by telephone. Data on hearing loss and type of hearing aid were provided by the hearing aid dispensing practice. Logistic regression analyses were performed to identify determinants of non-regular use and dissatisfaction. Eighty-five percent used their device(s) regularly, 12% only occasionally and 3% never. Eighty percent were satisfied with their aids. Non-regular use of hearing aids was significantly associated with age, gender, regional language, total duration of use, type of amplification, hearing aid category, hearing loss, and dissatisfaction with and difficulties in managing the aid. Dissatisfaction was associated with regional language, total duration of use, difficulties in managing the aid, and non-regular use. It was concluded that rates of regular hearing aid use and satisfaction are high in Switzerland.

Cochlear implants in single-sided deafness - clinical results of a Swiss multicentre study.

AIM OF THE STUDY: The aim of this multicentre, prospective, open, nonrandomised clinical trial was to demonstrate the clinical efficiency and outcomes of cochlear implants (CIs) in adult patients with post-lingual single-sided deafness (SSD). METHODS: A group of five left and five right SSD participants were investigated with various clinical tests and questionnaires before and 12 months after CI activation. Changes in hearing thresholds, speech understanding in noise, sound localisation, tinnitus (Tinnitus Handicap Inventory; THI), subjective hearing ability (Speech, Spatial and Qualities of Hearing Scale; SSQ), and quality of life (WHOQOL-BREF) were assessed. In addition, the pre- and postoperative results of the SSD patients were compared with an age- and gender-matched normal hearing control group. RESULTS: Surgery was uncomplicated in all patients. Two years after implantation, 9 of the 10 patients used their CI regularly for an average of more than 11 hours a day. A significant improvement in speech understanding in noise measured in the sound field using the Oldenburg sentence test could be demonstrated in the two situations in which patients with SSD experience the greatest difficulty: speech from the front and noise at the healthy ear, and speech to the implanted ear and noise from the front. The sound localisation test showed significant improvement of the mean localisation error and the root mean square error after CI activation. Furthermore, a significant reduction of the THI was measured, and the SSQ showed a significant improvement in the subscale speech comprehension and in the subscale spatial hearing. Also, quality of life measured with the WHOQOL-BREF showed a general improvement, which was significant in the global subscale. For this questionnaire, there was no significant difference between the normal-hearing control group and the patients after 12 months of CI use. CONCLUSION: This study confirmed the clinical benefit of cochlear implantation in patients with SSD. The significant improvement of speech understanding in noise, sound localisation, tinnitus perception, subjective hearing ability, and in particular the improved quality of life support the recommendation that patients with recently acquired SSD should be offered a CI. (Clinical trial registration number on clinicaltrial.gov: NCT01749592).

Transmission pathways of vibratory stimulation as measured by subjective thresholds and distortion-product otoacoustic emissions.

To clarify the contribution of the skull contents to the transmission of bone vibratory stimuli, and to examine the characteristics of such stimuli, we compared auditory thresholds and distortion-product otoacoustic emission (DPOAE) levels with a bone vibrator placed on various sites of the head, including the eye. The best audiometric thresholds and the highest DPOAE levels were obtained with the vibrator placed on the mastoid of the measuring side, or on the "ultrasound-window" of the temple. The audiometric thresholds obtained with the bone vibrator on the eye were similar to those of the forehead, and about 10 dB higher than at the best sites. DPOAEs were clearly present when elicited by a combination of air-conducted stimuli presented through an insert earphone and with the bone vibrator placed on the eye. These results indicate that vibratory sounds can be transmitted through the skull contents to the inner ear. The intracranial transmission pathway of the vibratory stimuli may play a significant role, particularly at low frequencies, and possibly also when the vibratory stimuli are applied on the skull bone.

Prognostic model for predicting hearing recovery in idiopathic sudden sensorineural hearing loss.

HYPOTHESIS: To aid in realistic counseling of patients at the time of their first visit concerning their chances for recovery, we created a simple prognostic model for predicting hearing recovery in idiopathic sudden sensorineural hearing loss (ISSHL). BACKGROUND: An important element of research on ISSHL is to identify prognostic factors for this disease. Many studies have described predictive indicators to identify patients with a good prognosis needing no or minimal treatment. Only a few of these studies have included a model for calculating the probability for patient recovery, which may be important for clinical work, but these prognostic tables have not achieved widespread use clinically. METHODS: Evaluation of an electronic patient data base of 541 patients with ISSHL. The standard treatment was carbogen inhalation (95% O2 and 5% CO2 8 times per day in duration of 30 min) and prednisone orally (100 mg in 1 morning dose) for 7 days. Factors that were analyzed included the patient's age, the interval between the onset of symptoms and beginning of treatment, the presence or absence of vertigo and tinnitus, audiometric patterns, the severity of hearing loss, and hearing in the opposite ear. Hearing gain was expressed either as absolute hearing gain or as relative hearing gain. Significant recovery of hearing was defined as the final pure-tone audiometry of 30 dB or less (or the same as the pure-tone audiometry of the opposite ear). RESULTS: The absolute hearing gain was 15.1 dB. The mean relative hearing gain was 47%. Three hundred one (57%) patients had significant recovery of hearing, and 228 (43%) did not have significant recovery of hearing. Using step-wise multiple linear regression analysis, the most important factors for prognosis included severity of hearing loss, presence of vertigo, time between onset and treatment, the hearing of the other ear, and the audiogram shape (beta coefficient was -0.216, -0.231, 0.211, 0.113, and -0.064, respectively; constant, 0.968). A recovery expectancy table was developed using the data from this study. CONCLUSION: Based on a retrospective analysis, prognostic indicators for hearing recovery in ISSHL were found to be severity of hearing loss, presence of vertigo, time between onset and treatment, the hearing of the other ear, and the audiogram shape. We created a model for calculating the probability for hearing recovery based on the analysis of 529 patients with unilateral ISSHL.

Right Ear Advantage of Speech Audiometry in Single-sided Deafness.

BACKGROUND: Postlingual single-sided deafness (SSD) is defined as normal hearing in one ear and severely impaired hearing in the other ear. A right ear advantage and dominance of the left hemisphere are well established findings in individuals with normal hearing and speech processing. Therefore, it seems plausible that a right ear advantage would exist in patients with SSD. METHODS: The audiometric database was searched to identify patients with SSD. Results from the German monosyllabic Freiburg word test and four-syllabic number test in quiet were evaluated. Results of right-sided SSD were compared with left-sided SSD. Statistical calculations were done with the Mann-Whitney U test. RESULTS: Four hundred and six patients with SSD were identified, 182 with right-sided and 224 with left-sided SSD. The two groups had similar pure-tone thresholds without significant differences. All test parameters of speech audiometry had better values for right ears (SSD left) when compared with left ears (SSD right). Statistically significant results (p < 0.05) were found for a weighted score (social index, 98.2 ±â€Š4% right and 97.5 ±â€Š4.7% left, p < 0.026), for word understanding at 60 dB SPL (95.2 ±â€Š8.7% right and 93.9 ±â€Š9.1% left, p < 0.035), and for the level at which 100% understanding was reached (61.5 ±â€Š10.1 dB SPL right and 63.8 ±â€Š11.1 dB SPL left, p < 0.022) on a performance-level function. CONCLUSION: A right ear advantage of speech audiometry was found in patients with SSD in this retrospective study of audiometric test results.

Evaluation of an Infant Temporal-Bone Model as Training Tool.

OBJECTIVE: Evaluation of the face validity of a new artificial model of an infant temporal bone (TB) suitable for surgical training, including cochlear implantation. SUBJECT: Micro-computer-tomography images were obtained from a TB specimen of a 1-year-old normal infant available in an anatomical collection. The TB model was designed and constructed using these images and techniques known from similar models of adult TB. INTERVENTION: Fifteen otology departments in Austria, Germany, and Switzerland rated the infant TB model and compared it with the established adult TB model manufactured commercially by the same company. MAIN OUTCOME MEASURE: The otologists responded to a semi-quantitative questionnaire with a rating scale ranging from 1 (strongly disagree) to 5 (strongly agree). Macroscopic and microscopic anatomic details, drilling experience, and surgical landmarks were rated. The surgical procedures included mastoidectomy, posterior tympanotomy, cochleostomy, and insertion of a cochlear electrode. RESULTS: Overall ratings were similar (3.9) for both the infant and the adult TB models, with ranges of 3.47 to 4.47 (infant model) and 3.5 to 4.33 (adult model). Ratings of specific anatomical details differed as a function of type of model, but without preference of one model over the other. CONCLUSIONS: Infant TB models can be used similarly as adult TB models for surgical training, including cochlear implantation. They may deserve a more important role in surgical training because cadaveric human temporal bones of infants are not available.

In-vivo assessment of osseous versus non-osseous transmission pathways of vibratory stimuli applied to the bone and the dura in humans.

BACKGROUND: Bone conduction (BC) is an alternative to air conduction (AC) for stimulation of the inner ear. Stimulation for BC can occur directly on the skull bone, on the skin covering the skull bone, or on soft tissue (i.e., eye, dura). All of these stimuli can elicit otoacoustic emissions (OAE). This study aims to compare OAEs generated by different combinations of stimuli in live humans, including direct stimulation of the intracranial contents via the dura, measured intraoperatively. METHODS: Measurements were performed in five normal-hearing ears of subjects undergoing a neurosurgical intervention with craniotomy in general anesthesia. Distortion product OAEs (DPOAEs) were measured for f2 at 0.7, 1, 2, 3, 4, and 6 kHz with a constant ratio of the primary frequencies (f2/f1) of 1.22. Sound pressure L1 was held constant at 65 dB SPL, while L2 was decreased in 10 dB steps from 70 to 30 dB SPL. A DPOAE was considered significant when its level was ≥6 dB above the noise floor. Emissions were generated sequentially with different modes of stimulation: 1) pre-operatively in the awake subject by two air-conducted tones (AC-AC); 2) within the same session preoperatively by one air- and one bone-conducted tone on the skin-covered temporal bone as in audiometry (AC-BC); 3) intra-operatively by one air-conducted tone and one bone-vibrator tone applied directly on the dura (AC-DC). A modified bone vibrator (Bonebridge; MED-EL, Innsbruck, Austria) was used for BC stimulation on the dura or skin-covered mastoid. Its equivalent perceived SPL was calibrated preoperatively for each individual by psychoacoustically comparing the level of a BC tone presented to the temporal region to an AC tone at the same frequency. Simultaneously with the DPOAEs, vibrations at the teeth were measured with an accelerometer attached using a custom-made holder. RESULTS: It was possible to record DPOAEs for all three stimulation modes. For AC-DC, DPOAEs were not detected above the noise floor below 2 kHz but were detectable at the higher frequencies. The best response was measured at or above 2 kHz with L2 = 60 dB SPL. The acceleration measured at the teeth for stimulation on the dura was lower than that for stimulation on the bone, especially below 3 kHz. CONCLUSION: We demonstrate a proof-of-concept comparison of DPOAEs and teeth acceleration levels elicited by a bone vibrator placed either against the skin-covered temporal bone, as in audiometry, or directly against the dura mater in patients undergoing a craniotomy. It was demonstrated that DPOAEs could be elicited via non-osseous pathways within the skull contents and that the required measurements could be performed intra-operatively.

Sheep as a large animal ear model: Middle-ear ossicular velocities and intracochlear sound pressure.

Animals are frequently used for the development and testing of new hearing devices. Dimensions of the middle ear and cochlea differ significantly between humans and commonly used animals, such as rodents or cats. The sheep cochlea is anatomically more like the human cochlea in size and number of turns. This study investigated the middle-ear ossicular velocities and intracochlear sound pressure (ICSP) in sheep temporal bones, with the aim of characterizing the sheep as an experimental model for implantable hearing devices. Measurements were made on fresh sheep temporal bones. Velocity responses of the middle ear ossicles at the umbo, long process of the incus and stapes footplate were measured in the frequency range of 0.25-8 kHz using a laser Doppler vibrometer system. Results were normalized by the corresponding sound pressure level in the external ear canal (PEC). Sequentially, ICSPs at the scala vestibuli and tympani were then recorded with custom MEMS-based hydrophones, while presenting identical acoustic stimuli. The sheep middle ear transmitted most effectively around 4.8 kHz, with a maximum stapes velocity of 0.2 mm/s/Pa. At the same frequency, the ICSP measurements in the scala vestibuli and tympani showed the maximum gain relative to the PEC (24 dB and 5 dB, respectively). The greatest pressure difference across the cochlear partition occurred between 4 and 6 kHz. A comparison between the results of this study and human reference data showed middle-ear resonance and best cochlear sensitivity at higher frequencies in sheep. In summary, sheep can be an appropriate large animal model for research and development of implantable hearing devices.

Long-term assessment after implantation of the Vibrant Soundbridge device.

OBJECTIVE: To present long-term results with a semi-implantable middle ear implant, the Vibrant Soundbridge (VSB), and analyze pre- and post-operative results of audiologic tests. STUDY DESIGN: Retrospective chart review with additional patient interview and audiologic testing. SETTING: One tertiary referral center. SUBJECTS: Twenty patients who met the selection criteria of the manufacturer were evaluated at least two years after implantation. INTERVENTIONS: Monaural Implantation of the VSB in 20 patients, in two of these 20 patients implantation of the second ear in a second stage. RESULTS: Assessment of benefit and satisfaction using the standardized International Outcome Inventory for Hearing Aids, the Glasgow Benefit Inventory, and Visual Analogue Scales in all patients. Fifteen patients agreed to undergo audiologic testing at follow-up including pure-tone- and speech audiometry in silence and noise. The majority of patients (13/20) reported to be satisfied or very satisfied with the VSB. Aided speech perception was comparable between the VSB and the hearing aid preoperatively. When compared to the preoperative audiograms, residual hearing from 0.5-4 kHz was significantly worse in the operated ear with 8 dB (Wilcoxon signed rank test p < 0.001) but only 2.6 dB in the non-operated ear (Wilcoxon signed rank test, p > 0.05). Major surgical complications did not occur. Permanent alteration in taste occurred in three patients and revision surgery was necessary in another three patients. CONCLUSION: Satisfaction with the VSB was not superior to conventional hearing aids in subjective and in audiometric terms. Because of its impact on residual hearing and the requirement of implantation middle ear surgery, implantation of the VSB should be limited to patients with relevant side effects of hearing aids, e.g., severe chronic otitis externa.

Detection of Helicobacter pylori in patients with head and neck cancer: Results from a prospective comparative study combining serology, polymerase chain reaction, and rapid urease test.

BACKGROUND: The purpose of this study was to evaluate prospectively the presence and impact of the gastric carcinogen Helicobacter pylori (H. pylori) in the upper aerodigestive tract. Previous studies suggested it could represent a risk factor for head and neck squamous cell carcinoma (HNSCC). METHODS: Serology, rapid urease test, and quantitative polymerase chain reaction (qPCR) for H. pylori were performed in patients with head and neck cancer (N = 56) and cancer-free controls (N = 90). Comparison between groups was done using logistic regression analysis. RESULTS: Rates of positive serology and rapid urease test did not differ between the 2 groups in logistic regression analysis (p = .677 and p = .633, respectively). Birth in a developing country and age above 50 years old were predictors of positive serology (p < .001 and p = .040, respectively). Using qPCR, no biopsy showed the presence of H. pylori. CONCLUSION: This study challenges the concept that H. pylori may be a risk factor for HNSCC.