Restoring speech intelligibility for hearing aid users with deep learning.

Almost half a billion people world-wide suffer from disabling hearing loss. While hearing aids can partially compensate for this, a large proportion of users struggle to understand speech in situations with background noise. Here, we present a deep learning-based algorithm that selectively suppresses noise while maintaining speech signals. The algorithm restores speech intelligibility for hearing aid users to the level of control subjects with normal hearing. It consists of a deep network that is trained on a large custom database of noisy speech signals and is further optimized by a neural architecture search, using a novel deep learning-based metric for speech intelligibility. The network achieves state-of-the-art denoising on a range of human-graded assessments, generalizes across different noise categories and-in contrast to classic beamforming approaches-operates on a single microphone. The system runs in real time on a laptop, suggesting that large-scale deployment on hearing aid chips could be achieved within a few years. Deep learning-based denoising therefore holds the potential to improve the quality of life of millions of hearing impaired people soon.

Identification of Neural Mechanisms in First Single-Sweep Analysis in oVEMPs and Novel Normative Data.

BACKGROUND: Bone-conducted (BC) VEMPs provide important tools for measuring otolith function. However, two major drawbacks of this method are encountered in clinical practice-small n10 amplitude and averaging technique. In this study, we present the results of a new VEMP setup measuring technique combined with a novel single-sweep analysis. METHODS: The study included BC oVEMP data from 92 participants for the evaluation of normative data using a novel analysis technique. For evaluating test-retest reliability, the intraclass correlation coefficient (ICC) was used. RESULTS: We found significant n10 amplitude differences in single-sweep analyses after the first and second measurements. Thereby, mathematical analyses of the head movement did not show any differences in the first or second measurements. The normative n10 amplitude was 20.66 µV with an asymmetric ratio (AR) of 7%. The new value of late shift difference (LSD) was 0.01 ms. The test retest-reliability showed good to excellent ICC results in 9 out of 10 measurements. CONCLUSIONS: Our results support a phenomenon in single-sweep analysis of the first stimuli independent of head movement and signal morphology. Furthermore, the values obtained with the new measurement method appear to be more sensitive and may allow an extended diagnostic range due to the new parameter LSD.

CO2 laser stapedotomy safety: influence of laser energy and time on bone-conduction hearing levels.

Total laser energy in CO2 stapedotomy depends on the laser settings and the amount of applications. It is unclear if the amount of total laser energy affects bone-conduction hearing thresholds and if possible effects are temporary or permanent. Alterations of bone-conduction hearing thresholds after single or multiple-shot CO2 laser stapedotomy were analyzed between 1 and 3 weeks and 1.5-6 months after primary (n = 501) or revision surgeries (n = 153) and correlated to time, laser energy, frequency, surgical technique, and pathology encountered in revision stapedotomy. In both time periods, most patients showed a lower bone-conduction threshold in the four-tone puretone average (PTA) at frequencies of 0.5, 1, 2, and 3 kHz that further improved over time. Between 1 and 3 weeks, the improvement was significant in subgroups with cumulative energies lower 1 J and successful one-shot technique or in revisions without laser application. The remaining subgroups with higher total energies showed significant improvements between 1.5 and 6 months. At 4 and 8 kHz, significant improvements were found during 1.5-6 months after primary and revision surgery independent of the used energy. Repeated CO2 laser applications showed no impairment in bone-conduction thresholds and can thus be considered as safe. In most patients, significant, yet unexplained, improvements in bone-conduction hearing thresholds were noticed in a time- and energy-related pattern.

Active middle ear implant coupled bilaterally to the round window despite bilateral implanted stapes prostheses.

After stapes surgery, patients with mixed or moderate hearing loss have limited possibilities for hearing improvement. We are reporting on a patient who underwent stapedotomy bilaterally 20 years ago and had sensorineural and mixed hearing loss. Recurrent otitis externa prevented the use of hearing aids. This patient was treated bilaterally with the Vibrant Soundbridge (Med-El, Innsbruck, Austria) successively. The Schuknecht piston stapes prostheses remained in situ. The Floating Mass Transducer (FMT; Med-El) was coupled to the round window (RW) and provided good acoustic reinforcement bilaterally. In conclusion, for patients with otosclerosis and stapes surgery, the FMT-RW coupling (Bess AG, Berlin, DE) is a safe procedure with good acoustic amplification. Laryngoscope, 2016 127:500-503, 2017.

Modification of unilateral otolith responses following spaceflight.

The aim of the study was to resolve the issue of spaceflight-induced, adaptive modification of the otolith system by measuring unilateral otolith responses in a pre- versus post-flight design. The study represents the first comprehensive approach to examining unilateral otolith function following space flight. Ten astronauts participated in unilateral otolith function tests three times preflight and up to four times after Shuttle flights from landing day through the subsequent 10 days. During unilateral centrifugation, utricular function was examined by the perceptual changes reflected by the subjective visual vertical (SVV) and the otolith-mediated ocular counter-roll, designated as utriculo-ocular response (UOR). Unilateral saccular reflexes were recorded by measurement of collic vestibular evoked myogenic potentials (cVEMP). The findings demonstrate a general increase in interlabyrinth asymmetry of otolith responses on landing day relative to preflight baseline, with subsequent reversal in asymmetry within 2-3 days. Recovery to baseline levels was achieved within 10 days. This fluctuation in asymmetry was consistent for the utricle tests (SVV and UOR) while apparently stronger for SVV. A similar asymmetry was observed during cVEMP testing. In addition, the results provide initial evidence of a dominant labyrinth. The findings require reconsideration of the otolith asymmetry hypothesis; in general, on landing day, the response from one labyrinth was equivalent to preflight values, while the other showed considerable discrepancy. The finding that one otolith response can return to one-g level within hours after re-entry while the other takes considerably longer demonstrates the importance of considering the otolith response as a result of both peripheral and associated central neural processing.

CO2 laser revision stapedotomy.

OBJECTIVES/HYPOTHESIS: To evaluate the safety and efficacy of the one-shot noncontact technique in stapedotomy for revision stapes surgery with a CO2 laser combined with a scanning system. STUDY DESIGN: Prospective study. METHODS: Intraoperative findings and hearing results of 106 patients who underwent revision CO2 laser stapedotomy because of conductive or sensorineural hearing loss or vertigo were analyzed. RESULTS: Leading pathologies were displacement of the prosthesis, incus erosion, fibrous adhesions, and bony reobliteration or a too long or too short prosthesis. Surgery was successfully performed in all cases with a noncontact technique resulting in significantly improved postoperative air and bone conduction. The rate of permanent complications was 0.9%. A comparison of the effect of higher laser energies used for the perforation of bony stapes footplates and lower energies for neomembranes revealed no significant difference in hearing results, underscoring the safety of the technique. CONCLUSIONS: To avoid any manipulation of the conductive hearing chain that may cause sensorineural hearing loss, we adapted the noncontact technique previously introduced by us for use in revision stapedotomy. This technique was successfully applied to improve conductive and sensorineural hearing loss as well as vertigo in first and second revision stapedotomy cases. Because the rate of postoperative complications was comparable to what is achieved with other laser systems, we conclude that the method has at least an equal level of safety. In conclusion, we advocate the use of a noncontact technique as suitable for an early revision of failed stapedotomy.

A clinical study of the subjective visual vertical during unilateral centrifugation and static tilt.

CONCLUSION: The present study demonstrates that various response patterns of subjective visual vertical (SVV) can be identified during unilateral centrifugation (UC). It is proposed that these response types correspond to different degrees of compensation after disease. This is advantageous for monitoring the effect of rehabilitative measures and is useful in medico-legal issues. It also emerges that diagnosis of unilateral utricle function requires the determination not only of asymmetry ratio but also offset of SVV estimates. OBJECTIVES: A retrospective clinical study of SVV test results was performed to establish a classification and model of response types in patients with suspected otolith disorder. METHODS: SVV measurements were made in 473 patients recruited from the dizziness clinic. A control group of healthy subjects (n = 43) was tested with the same protocol. Testing with bilateral stimulation (stationary upright, 15°, 30° tilt) and UC was performed. A mathematical model for the UC results was developed. RESULTS: During UC testing 61% of the patients showed an asymmetric response indicating a unilateral utricular hypofunction/dysfunction. These results could be classified into three subgroups, indicating different degrees of compensation. The model parameters can be adapted to reflect this classification.

Evidence of unilateral isolated utricular hypofunction.

CONCLUSIONS: The findings demonstrate that an enduring unilateral utricular dysfunction, possibly together with canal hypofunction, can occur after labyrinthine disease or injury. They also suggest that unilateral, isolated utricular dysfunction - or utricle paresis - can occur, representing a novel entity in the differential diagnosis of peripheral vestibular function. The occurrence of subjective visual vertical (SVV) asymmetry in the presence of symmetric vestibular evoked myogenic potentials (VEMPs) also confirms that the information from the utricles, rather than the saccules, dominates SVV estimation. OBJECTIVES: To determine the incidence of unilateral utricular hypofunction. METHODS: The retrospective clinical study deals with a selection of those vestibular patients who showed pathological responses to utricle testing. Peripheral vestibular function was examined in a group of 110 patients. Utricular function was evaluated by estimation of SVV during unilateral centrifugation. Bithermal caloric testing was performed to assess unilateral semicircular canal function. Saccular function was tested by measurement of VEMPs. RESULTS: A total of 46 patients were found with asymmetric SVV findings (p < 0.001 for healthy versus lesioned ear), but symmetric caloric responses and VEMPs. Statistical testing also verified that their SVV asymmetry factors were significantly higher than those calculated for caloric responses and VEMPs (p < 0.001).

Treatment of Ménière's disease by low-dosage intratympanic gentamicin application: effect on otolith function.

OBJECTIVES: The intratympanic application of a low dosage of gentamicin is increasingly favored as treatment for Ménière's disease. While posttreatment observations have confirmed a long-term success of the therapy of vertigo attacks, clear differences in the posttreatment recovery interval can be observed. In addition to differences in central-vestibular compensation, the degree of peripheral vestibular damage, i.e., to the saccule, utricle, and semicircular canal ampullae, varies among patients. This study provides comprehensive pre- and posttreatment results from unilateral functional tests of the individual vestibular receptors and of the cochlea in patients with Ménière's disease. STUDY DESIGN: Prospective clinical study. METHODS: Nineteen patients with unilateral Ménière's disease were treated by intratympanic application of gentamicin by injection of 0.3 mL (12 mg) through the tympanic membrane under local anesthesia. Tests were performed immediately previous to treatment and subsequently in the periods 4 to 8 weeks and 12 to 16 weeks after treatment. Unilateral saccular function was tested by means of acoustic-click, vestibular-evoked myogenic potentials (VEMP), and unilateral utricular function by subjective visual vertical (SVV) during unilateral centrifugation. Bithermal caloric testing was performed to assess unilateral semicircular canal function. RESULTS: Prior to gentamicin treatment, the caloric response from the diseased ear was normal in 3 patients, below normal in 14 patients, and in 2 cases almost completely absent. VEMP responses could be recorded bilaterally in 13 patients; while in 6, no VEMPs could be measured from the diseased ear. Utricular function measured by SVV estimation was found to be normal in 11 patients and marginally abnormal in 2 patients. In six cases, the SVV was clearly underestimated during centrifugation of the diseased side. The posttreatment findings demonstrate that VEMPs were absent in all treated patients, and the caloric response was abnormally low in all but one case. In contrast, only 12 of 19 patients produced abnormal SVV responses. CONCLUSION: The results demonstrate that incremental, intratympanic application of gentamicin effectively eliminates semicircular canal and saccular function. In contrast, utricular function appears to be maintained in 30 to 40% of cases.

Utricular dysfunction in patients with benign paroxysmal positional vertigo.

OBJECTIVE: The objective of this study was to test the hypothesis that utricular function is impaired in patients with idiopathic benign paroxysmal positional vertigo. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary dizziness clinic and vestibular research laboratory. PATIENTS: Twelve patients with unilateral idiopathic benign paroxysmal positional vertigo were examined 1 week and 1 month after successful treatment with positioning maneuvers and compared with 24 healthy subjects. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Otolith function was assessed with estimation of the subjective visual vertical and analysis of the torsional otolith-ocular reflex. Unilateral stimulation of the utricle was performed on a rotator that allowed eccentric lateral displacement of the patient during earth-vertical rotation with constant velocity. The otolith-ocular reflex was recorded with three-dimensional video-oculography. RESULTS: There was no difference in the estimation of the subjective visual vertical between patients and controls. The peak-to-peak amplitude of the otolith-ocular reflex torsional eye position was smaller in patients than in the control group. The gain of the unilateral otolith-ocular reflex was reduced in patients on both sides on first testing. After several weeks, only the affected labyrinth showed a reduced otolith-ocular reflex gain. CONCLUSION: Our findings document otolith dysfunction in patients with idiopathic benign paroxysmal positional vertigo possibly secondary to degeneration of the utricular macula. This finding may account for the transient mild imbalance and dizziness that some patients with benign paroxysmal positional vertigo experience even after resolution of positional vertigo.