Correlation of Superior Canal Dehiscence Surface Area With Vestibular Evoked Myogenic Potentials, Audiometric Thresholds, and Dizziness Handicap.

Objective: To correlate objective measures of vestibular and audiometric function as well as subjective measures of dizziness handicap with the surface area of the superior canal dehiscence (SCD). Study Design: Retrospective chart review and radiological analysis. Setting: Single tertiary academic referral center. Patients: Preoperative computed tomography imaging, patient survey, audiometric thresholds, and vestibular evoked myogenic potential (VEMP) testing in patients with confirmed SCD. Intervention(s): Image analysis techniques were developed to measure the surface area of each SCD in computed tomography imaging. Main Outcome Measure(s): Preoperative ocular and cervical VEMPs, air and bone conduction thresholds, air-bone gap, dizziness handicap inventory scores, and surface area of the SCD. Results: Fifty-three patients (mean age 52.7 yr) with 84 SCD were analyzed. The median surface area of dehiscence was 1.44 mm2 (0.068-8.23 mm2). Ocular VEMP amplitudes (r = 0.61, p

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Anatomic Variations in Temporal Bones Affect the Intensity of Nystagmus During Warm Caloric Irrigation.

Hypothesis: Anatomic variables within the mastoid will correlate with intensity of caloric responses. Background: During caloric irrigation, heat is transferred from the external auditory canal to the lateral semicircular canal (LSCC) through aerated mastoid bone. Temporal bone airspace volume and bone volume vary widely but the effect of this variation on caloric irrigation testing is not well characterized. Understanding this effect is necessary to understand how mastoid surgery may alter caloric irrigation results. Methods: Twenty-two mastoid airspace and bones, as well as LSCC, were reconstructed from computed tomography scans of 11 subjects with normal anatomy who underwent vestibular function evaluation. Respective surface area (SA) and volume (V) of the mastoid airspace, bones, LSCC, and distance from LSCC to tympanic membrane (LSCC-TM) were calculated. In addition, computed values from these anatomic structures were correlated with the maximum velocity of slow phase nystagmus during warm caloric irrigation (MVwarm). Results: Our results showed that the combined effect of airspace SA:V, bone SA:V, LSCC SA:V, and LSCC-TM distance accounted for 69.5% of the variation in MVwarm. Airspace SA:V (R2 = 0.22) and LSCC SA:V (R2 = 0.02) positively correlated with MVwarm, while bone SA:V (R2 = 0.17) demonstrated an inverse correlation with MVwarm. Conclusion: Preliminary results from this pilot study suggest that a substantial amount of the variability in MVwarm can be explained by temporal bone anatomy. Results also indicate that the denser the bone, the more heat is transferred to the LSSC, whereas increased airspace serves as an insulator. A larger study is necessary to confirm our findings. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Role of Facial Nerve Motor-Evoked Potential Ratio in Predicting Facial Nerve Function in Vestibular Schwannoma Surgery Both Immediate and at 1 Year.

Objective: To determine whether transcranial electrical stimulation-induced facial motor-evoked potential (FMEP) monitoring of the facial nerve (FN) during vestibular schwannoma (VS) tumor resection can predict both immediate and 1 year postoperative FN functional outcome. Design: Prospective consecutive non-comparative observational case series. Setting: Tertiary referral center. Main Outcome Measures: Facial function, immediate post operation and at 1 year using House-Brackmann (HB) grading scale. Methods: The study included 367 consecutive patients (men 178; women 189; age 13-81 years) monitored during primary sporadic VS microsurgery between November 2002 and April 2015. Neurofibromatosis type II, revision surgery, previous radiotherapy treatment, preoperative facial nerve weakness, and non-VS cases were excluded retrospectively during analysis of data. Data of facial function were missing from eight patients at 1 year and were excluded. The correlation between the final-to-baseline FMEP ratio and immediate and 1 year facial nerve function was examined. Results: Using logistic regression model, the cut-off points of FMEP ratio were 0.62 (PPV 0.96) and 0.59 (PPV 0.98) which predicted satisfactory FN function (HB grades 1 or 2) immediately postoperative and at 1 year after surgery, respectively. Conclusion: Transcranial electrical stimulation FMEP is a valuable tool for monitoring facial nerve function during resection of vestibular schwannoma. Maintaining a FMEP event-to-baseline ratio of 60% or greater is predictive of satisfactory long-term FN function. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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The Effect of Round Window Sealants on Delayed Hearing Loss in a Guinea Pig Model of Cochlear Implantation.

Aim: To determine whether the type of material used to seal the cochlea after round window cochlear implantation influences delayed hearing loss. Background: Cochlear implants are now prescribed to patients with residual, low-frequency hearing. This hearing-which provides perceptual benefits for the implanted ear-is frequently lost for unknown reasons weeks to months after surgery in a proportion of patients. A post-surgical change in cochlear mechanics, related to the material used to seal the cochlea after round window implantation, may contribute to this loss. Methods: An electrode array was implanted in guinea pigs via the round window, which was then sealed with muscle, periosteum, or fibrin glue. Auditory brainstem responses (ABRs) to pure tones (2, 8, 16, 24, and 32 kHz) were recorded before surgery and 1, 4, and 12 weeks after surgery, with subjects then euthanized and their cochleae harvested for histological analysis. Results: Muscle and periosteum, but not fibrin glue, exhibited delayed threshold rises at 2 kHz. Twelve weeks after implantation, 2 kHz threshold shifts differed significantly between muscle (mean, 27.1 dB) and fibrin glue (9.3 dB), but not between these groups and periosteum (19.3 dB). Muscle was sometimes associated with much greater tissue reactions than the other sealants. Most cochleae had injuries to the basilar membrane and/or osseous spiral lamina, regardless of sealant. Hair cell counts did not differ significantly among sealants. Conclusion: Delayed, low-frequency hearing loss was observed when cochleae were sealed with muscle or periosteum, but not when cochleae were sealed with fibrin glue. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Electrode Location and Audiologic Performance After Cochlear Implantation: A Comparative Study Between Nucleus CI422 and CI512 Electrode Arrays.

Objectives: 1) Compare rates of scala tympani (ST) insertion between Nucleus CI422 Slim Straight electrodes and Nucleus CI512 Contour Advance electrodes; 2) examine audiometric performance with both electrode arrays, while controlling for electrode location. Setting: Tertiary academic hospital. Patients: Fifty-six post-lingually deafened adults undergoing cochlear implant (CI). Main Outcome Measures: Primary outcome measures of interest were scalar electrode location and postoperative audiologic performance. Results: Fifty-six implants in 49 patients were included; 20 were implanted with Nucleus CI422 Slim Straight electrodes, and 36 were implanted with Nucleus CI512 Contour Advance electrodes. Overall, 62.5% (35 of 56) of implants had all electrodes located within the ST. Significantly, higher rates of ST insertion (90%) were observed for Nucleus CI422 Slim Straight electrodes when compared with Nucleus CI512 Contour Advance electrodes (47.2%) (p = 0.002). In regards to audiologic performance, consonant-nucleus-consonant (CNC) scores were significantly higher for Nucleus CI422 Slim Straight electrodes (55.4%) compared with Nucleus CI512 Contour Advance electrodes (36.5%) (p = 0.005). In addition, AzBio scores were better for Nucleus CI422 Slim Straight electrodes (71.2%) when compared with Nucleus CI512 Contour Advance electrodes (46.7%) (p = 0.004). Controlling for ST insertion, higher AzBio scores were again observed for Nucleus CI422 Slim Straight electrodes (p = 0.02). Conclusions: The results of this study demonstrate that the Nucleus CI422 Slim Straight electrode is more likely to reside entirely within the ST when compared with the Nucleus CI512 Contour Advance electrode. Furthermore, AzBio scores were superior for patients with Nucleus CI422 Slim Straight electrodes in all patients, as well as those with only ST insertions. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Tension Pneumocephalus Related to Spontaneous Skull Base Dehiscence in a Patient on BiPAP.

No abstract available

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Drug Diffusion to the Apex of the Human Cochlea? A Comment on "Kang WS, Nguyen K, McKenna CE, Sewell WF, McKenna MJ, Jung DH. Intracochlear Drug Delivery Through the Oval Window in Fresh Cadaveric Human Temporal Bones".

No abstract available

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Experiences Engaging Healthcare When Dizzy.

Objective: Dizziness is a common yet difficult symptom to manage in patients seeking medical care. The purpose of this study was to describe the experiences of participants with dizziness engaging the medical community for help. Patients: Five hundred twenty one participants were recruited from the Vestibular Disorder Association (VEDA) website using the association's list-serve, social media (Facebook), and fliers distributed through healthcare providers. Intervention: NA. Main Outcome Measure: Data related to diagnostics, treatment, quality of life, and healthcare costs as developed by a task force of selected vestibular specialists. Results: Meniere's disease, vestibular migraine, and vestibular neuritis/labyrinthitis were the top three self-reported diagnoses that caused dizziness. Over 40% of participants sought medical care within 1 week of onset (acute stage) yet greater than 50% required 5 months or longer to reach a diagnosis. Only 20% of the participants felt their diagnosis was accurate and timely. Nearly 75% of participants reported having magnetic resonance imaging (MRI). Roughly 55% reported a fall as a result of their dizziness. Participants reported spending more money on their healthcare than did their third party payers. Conclusion: Our data show a large variability in when the symptom of dizziness was reported and when a diagnosis was made, with overall long diagnosis times and frequent referrals to multiple specialists. Additionally, many different healthcare providers were identified as diagnosing and treating dizziness yet one-third of participants were frustrated with being misdiagnosed or misdirected. Frequent MRIs despite their inaccuracy at diagnosing vestibular disorders, and overuse of canalith repositioning maneuvers, suggest diagnostic inefficiency. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Quality of Information Available Via the Internet for Patients With Otological Conditions.

Objective: Evaluate the type, content, and quality of information available via the Internet for patients with common otological conditions. Methods: The Google search engine was used to generate responses for the following search terms: glue ear, otitis media, otosclerosis, Meniere's disease, cholesteatoma, and ear perforation. The first 10 websites for each search term were selected for analysis. Websites were evaluated with the validated DISCERN instrument (Institute of Health Sciences, University of Oxford, UK), the LIDA tool (Minervation Ltd, Oxford, UK), the Flesch Readability Formula, the Simple Measure Of Gobbledygook (SMOG) readability score, and against the Journal of the American Medical Association (JAMA) criteria. Comparisons were made with a similar study assessing quality of information in nonotological conditions. Results: Mean SMOG score was 12.19 years of education (range, 6.2-22.8). The health on the net (HON) symbol appeared on 15 of 49 websites (30.61%). Pearson's r was used to identify interactions between variables and demonstrated a significant correlation between LIDA score and Google ranking (R2 = -0.1195, p = 0.002); between university/hospital affiliation and JAMA score (R2 = -1.7889, p = 0.0182) and commercial affiliation and JAMA score (R2 = 1.0561; p = 0.01). Multivariate linear regression analysis showed LIDA to be the strongest predictor of Google ranking (Page rank decreasing by 0.10572 per LIDA score; p = 0.01). Conclusion: As websites with better Google ranking were only weakly associated with higher quality rankings patients would benefit from being directed to reliable websites by clinicians. There is currently a gap in the available resources for a high quality repository of otological information aimed at patients. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Detection of Saccular Endolymphatic Hydrops in Meniere's Disease Using a Modified Glycerol cVEMP Test in Combination With the Tuning Property Test.

Objective: To determine the optimal method for detecting saccular endolymphatic hydrops (EH) in patients with Meniere's disease (MD) using a glycerol cervical vestibular evoked myogenic potential (cVEMP) test in combination with a tuning property test. Study Design: Prospective patients series. Setting: Tertiary referral center. Patients: Twenty-three subjects (age: 36-77 years) were enrolled in this study. Seventeen subjects were diagnosed with definite MD. Six subjects were diagnosed with possible MD. Intervention: Diagnostic. Main Outcome Measure: The corrected amplitudes of p13-n23 (cVEMP) were measured before and after the administration of 10% glycerol (500 ml, 2 h, intravenously). A tuning property index and the p13-n23 amplitude improvement ratio were calculated. Results: The positivity rate (PR) during the tuning property test was 55% (definite MD-affected ears), 35% (definite MD-unaffected ears), and 25% (possible MD ears). The PR during the glycerol cVEMP amplitude test was 60, 8, and 0%, respectively. The use of modified criteria for the glycerol cVEMP test in combination with the tuning property test resulted in the PR increasing to 75, 57, and 25%, respectively. The pre-glycerol stage results obtained using the tuning property test almost (except in two ears) completely agreed with the glycerol cVEMP test results by the modified criteria. Conclusion: The tuning property test is an easy and useful way of detecting saccular EH. However, the glycerol cVEMP test is required in patients that do not respond to either 500 or 1000 Hz short tone bursts (STB). Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Transcanal Endoscopic Ear Surgery for the Management of Congenital Ossicular Fixation.

Objectives: 1) To describe the technique for transcanal endoscopic management of congenital ossicular chain fixation. 2) To highlight the utility and outcomes of the endoscopic approach for management of congenital ossicular fixation. Study Design: Retrospective patient series. Setting: Academic tertiary pediatric hospital. Patients: Pediatric patients (age 6-12) undergoing transcanal endoscopic management of congenital ossicular fixation from May 2014 to December 2014. Interventions: A transcanal endoscopic approach was used in eight procedures. Ossicular chain pathology was managed with either mobilization, ossiculoplasty with a stapes prosthesis, or incus interposition. Main Outcome Measures: Pure-tone averages, speech reception thresholds, and speech discrimination scores were recorded pre- and postoperatively for each subject. Preoperative computed tomography evaluations were compared to intraoperative findings for each subject. Results: An improvement in the pure-tone average, as well as air-bone gap, was noted after six of eight procedures. No patients experienced a complication or a reduction in their bone conduction hearing. The chorda tympani nerve was preserved in all eight patients. Conversion to open approach was not necessary for any of the eight procedures performed. Conclusion: The transcanal endoscopic approach was successful in improving hearing in pediatric patients with congenital ossicular fixation that involves any of the three ossicles. An endoscopic transcanal approach provides an alternative method to manage congenital ossicular pathology with the advantage of providing excellent visualization and the avoidance of a postauricular incision. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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The Underlying Mechanism of Preventing Facial Nerve Stimulation by Triphasic Pulse Stimulation in Cochlear Implant Users Assessed With Objective Measure.

Hypothesis: Triphasic pulse stimulation prevents from facial nerve stimulation (FNS) because of a different electromyographic input-output function compared with biphasic pulse stimulation. Background: FNS is sometimes observed in cochlear implant users as an unwanted side effect of electrical stimulation of the auditory nerve. The common stimulation applied in current cochlear implant consists of biphasic pulse patterns. Two common clinical remedies to prevent unpleasant FNS caused by activation of certain electrodes are to expand their pulse phase duration or simply deactivate them. Unfortunately, in some patients these methods do not provide sufficient FNS prevention. In these patients triphasic pulse can prevent from FNS. The underlying mechanism is yet unclear. Methods: Electromyographic (EMG) recordings of muscles innervated by the facial nerve (musculi orbicularis ori and oculi) were applied to quantitatively assess the effects on FNS. Triphasic and biphasic fitting maps were compared in four subjects with severe FNS. Based on the recordings, a model is presented which intends to explain the beneficial effects of triphasic pulse application. Results: Triphasic stimulation provided by fitting of an OPUS 2 speech processor device. For three patients, EMG was successfully recorded depending on stimulation level up to uncomfortable and intolerable FNS stimulation as upper boarder. The obtained EMG recordings demonstrated high individual variability. However, a difference between the input-output function for biphasic and triphasic pulse stimulation was visually observable. Compared with standard biphasic stimulation, triphasic pulses require higher stimulation levels to elicit an equal amount of FNS, as reflected by EMG amplitudes. In addition, we assume a steeper slope of the input-output function for biphasic pulse stimulation compared with triphasic pulse stimulation. Conclusion: Triphasic pulse stimulation prevents from FNS because of a smaller gradient of EMG input-output function compared with biphasic pulse stimulation. The underlying mechanism can be modeled by differences in spatiotemporal spread of the electrical field. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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High Resolution MRI Shows Presence of Endolymphatic Hydrops in Patients Still Symptomatic After Endolymphatic Shunt Surgery.

Objective: Endolymphatic hydrops has been well described in patients with Meniere's syndrome; however, causation has not been established. Decompression of the endolymphatic sac has been proposed as a means to relieve hydrops and improve vertigo symptoms, but the efficacy of the surgery is debated. Until recently, there have been few objective measures of efficacy other than patients' subjective symptoms. Recent archival human temporal bone studies have shown that patients continue to have hydrops after shunt surgery. We propose using high-resolution magnetic resonance imaging (MRI) to determine the efficacy of endolymphatic shunt surgery (ELS) in patients who continue to experience vertigo. Patients: Four patients presented with continued vertigo after ELS. Interventions: Magnetic resonance imaging sequences included "cisternographic" three-dimensional T2, and delayed intravenous-enhanced three-dimensional fluid-attenuation inversion recovery (DIVE-3D-FLAIR) sequences, performed with 2350 ms (bright perilymph) and 2050 ms (bright endolymph) inversion times. The bright endolymph images were subtracted from bright perilymph images to create a composite image with bright perilymph, dark endolymph, and intermediate bone signals. Main Outcome Measures: MRI finding of endolymphatic hydrops. Results: In all five affected ears in four patients who continued to experience severe vertigo, hydrops was found on high resolution MRI on the operated ear. The appearance on MRI was no different than in patients with endolymphatic hydrops (EH) who have not had surgery. Conclusions: The present study demonstrates the persistence of endolymphatic hydrops in patients who have failed ELS. Future studies evaluating for the presence or absence of endolymphatic hydrops in patients who claim to obtain relief from ELS. Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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Prevalence of Barotrauma in Recreational Scuba Divers After Repetitive Saltwater Dives.

Introduction: The aim was to investigate the prevalence of middle ear barotrauma (MEB) and to establish risk factors of MEB after repeated saltwater dives. Methods: In this prospective observational cohort study 28 divers were examined over 6 consecutive days of diving in the Red Sea, Egypt. Participants underwent an otoscopic examination before the first dive, between each dive and after the last dive. In addition, they performed Valsalva maneuver (VM) and were questioned about dive-related complaints. Otoscopic findings were classified according to TEED classification for MEB (0 = normal otoscopy to 4 = perforation) separately for each ear. First examination was conducted before the first dive. Final examination, including a questionnaire, was conducted at least 12 h after the last dive. Results: In total, 436 dives were performed and 1161 otoscopic findings were analyzed. All participants showed a normal eardrum and a positive VM during initial exam. MEB prevalence (TEED >0) was 36.5% at final examination. Prevalence increased significantly with number of dives per day (p 0.05). More experienced divers (>200 dives lifetime) showed significantly less barotrauma (p

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Outer Hair Cell Molecular Protein, Prestin, as a Serum Biomarker for Hearing Loss: Proof of Concept.

Hypothesis: At present there are no serum biomarkers available to monitor cochlear health in those at risk of hearing loss. Outer hair cells (OHCs) play an important role in cochlear function and are one of the cellular elements most vulnerable to damage, such as acoustic trauma. We hypothesized that an OHC-specific protein can serve as a biomarker for OHC damage in circulation. Methods: After assessing auditory function, rats were exposed to intense octave band noise for 2 to 3 hours. Auditory function was assessed 14 days after trauma. Blood samples were collected and prestin concentration was measured using enzyme-linked immunosorbent assay. Results: Circulating prestin was detectable in all control and noise-exposed animals. At 14 days after trauma, however, noise-exposed rats demonstrated statistically significant decrease in prestin concentrations compared with control animals. Conclusion: This work, for the first time, provides proof of concept that an otologic serum biomarker level can change after acoustic trauma and hearing loss. Our approach represents an entirely novel strategy in hearing diagnostics and has both research and clinical potential. Further work is needed to map out the temporal course of change in serum prestin concentrations after inner ear trauma, better define the relationship of serological and functional changes, and explore application to other etiologies of hearing loss (e.g., ototoxins). Copyright (C) 2016 by Otology & Neurotology, Inc. Image copyright (C) 2010 Wolters Kluwer Health/Anatomical Chart Company

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[Mental health problems of mothers and fathers of the deaf children with cochlear implants].

Related Articles

[Mental health problems of mothers and fathers of the deaf children with cochlear implants].

Otolaryngol Pol. 2014 May-Jun;68(3):135-42

Authors: Kobosko J, Geremek-Samsonowicz A, Skarżyński H

Abstract
INTRODUCTION: Child's deafness is a risk factor for the mental health of its parents. This study addresses a question whether mothers and fathers of the prelingually deaf children using cochlear implants (CI) experience a different intensity of psychopathology symptoms than parents of the hearing, typically developing children, and also if the intensity of those symptoms experienced by parents is related to how long their child is a cochlear implant user.
MATERIAL AND METHODS: In this study participated 153 hearing parents of the deaf children using a single cochlear implant (111 mothers, 42 fathers), and parents of the hearing children. Mean age of deaf children was 72 months, cochlear implant use duration was between 1 and 124 months. The control group of parents has been selected taking into account their typically developing child's sex and age. The parents' mental health has been assessed with Goldberg General Health Questionnaire GHQ-28 in Polish adaptation.
RESULTS: Mothers of deaf, CI using children experience significantly more symptoms of anxiety and insomnia compared to the mothers of typically developing children, while fathers of these children show the tendency for the increased level of depression symptoms compared to the fathers from the control group. In the group of deaf CI children mothers relate substantially more somatic and anxiety symptoms than fathers, whereas level of experiencing depression symptoms and problems in everyday functioning is similar in mothers and fathers. No relation between the duration of child's CI use and parents' mental health has been ascertained.
CONCLUSIONS: The mental health of parents of the deaf CI using children indicates that both mothers and fathers have problems in this sphere related to their child's deafness, but not to the duration of child's CI use. Parents of deaf, CI using children may need psychological help regardless of the time their child has been using the cochlear implant.

PMID: 24837909 [PubMed - indexed for MEDLINE]

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Relative velocity measurement from the spectral phase of a match-filtered linear frequency modulated pulse

Linear frequency modulated signals are commonly used to perform underwater acoustic measurements since they can achieve high signal-to-noise ratios with relatively low source levels. However, such signals present a drawback if the source or receiver or target is moving. The Doppler effect affects signal amplitude, delay, and resolution. To perform a correct match filtering that includes the Doppler shift requires prior knowledge of the relative velocity. In this paper, the relative velocity is extracted directly from the Doppler cross-power spectrum. More precisely, the quadratic coefficient of the Doppler cross-power-spectrum phase is proportional to the relative velocity. The proposed method achieves velocity estimates that compare favorably with Global Positioning System ground truth and the ambiguity method.

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Cochlear hearing loss and the detection of sinusoidal versus random amplitude modulation

This study assessed the effect of cochlear hearing loss on detection of random and sinusoidal amplitude modulation. Listeners with hearing loss and normal-hearing listeners (eight per group) generated temporal modulation transfer functions (TMTFs) for envelope fluctuations carried by a 2000-Hz pure tone. TMTFs for the two groups were similar at low modulation rates but diverged at higher rates presumably because of differences in frequency selectivity. For both groups, detection of random modulation was poorer than for sinusoidal modulation at lower rates but the reverse occurred at higher rates. No evidence was found that cochlear hearing loss, per se, affects modulation detection.

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Acoustic radiation force expressed using complex phase shifts and momentum-transfer cross sections

Acoustic radiation force is expressed using complex phase shifts of partial wave scattering functions and the momentum-transfer cross section, herein incorporated into acoustics from quantum mechanisms. Imaginary parts of the phase shifts represent dissipation in the object and/or in the boundary layer adjacent to the object. The formula simplifies the force as summation of functions of complex phase shifts of adjacent partial waves involving differences of real parts and sums of imaginary parts, providing an efficient way of exploring the force parameter-space. The formula for the force is proportional to a generalized momentum-transfer cross section for plane waves and no dissipation.

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Experimental validation of a three-dimensional reduced-order continuum model of phonation

Due to the complex nature of the phonation process, a one-dimensional (1D) glottal flow description is often used in current phonation models. Although widely used in voice research, these 1D flow-based phonation models have not been rigorously validated against experiments. In this study, a 1D glottal flow model is coupled with a three-dimensional nonlinear continuum model of the vocal fold and its predictions are compared to physical model experiments. The results show that the 1D flow-based model is able to predict the phonation threshold pressure and onset frequency within reasonable accuracy and to reproduce major vibratory features observed in the experiments.

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