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OBJECTIVE: Many patients with cochlear implants (CI) and auditory brainstem implants (ABI) require magnetic resonance imaging (MRI) following implantation. This study explores the patient experience of MRI, identifying factors associated with pain, and the effect of interventions designed to enhance comfort and safety.METHODS: A prospective observational case series from a tertiary referral unit. Tight head bandaging ± local anaesthetic injection (devices with non-MRI-compatible magnets) or observation alone (implants with MRI-compatible magnets) were employed for 1.5 T MRI of consecutive adult patients with CI or ABI without magnet removal. Pain was recorded via visual analogue scale (1 = no pain, 5 = extreme pain) at three time points; (1) baseline, (2) head bandage applied (3) during scanning. Patient age, device type, body area imaged and total scan time were recorded as variables, alongside adverse events.RESULTS: Data were collected for 227 MRI scans (34 patients with ABI, 32 with CI). In patients managed with bandaging, pain score after bandaging but prior to scanning (median 2.2) did not differ from pain during scanning (2.1), but both were significantly higher than baseline (1.4, both P ≤ 0.001). Scanning areas other than the head/cervical spine was associated with higher pain scores (P = 0.036). Pain during MRI differed between different manufacturers implants (P ≤ 0.001). Adverse events occurred in 8/227 scans (3.5%), none occurring with devices containing an MRI-compatible magnet.CONCLUSION: MRI scanning with auditory implant magnets in situ is safe and well tolerated by patients.

OBJECTIVE Preoperative differentiation of facial nerve schwannoma (FNS) from vestibular schwannoma (VS) can be challenging, and failure to differentiate between these two pathologies can result in potentially avoidable facial nerve injury. This study presents the combined experience of two high-volume centers in the management of intraoperatively diagnosed FNSs. The authors highlight clinical and imaging features that can distinguish FNS from VS and provide an algorithm to help manage intraoperatively diagnosed FNS. METHODS Operative records of 1484 presumed sporadic VS resections between January 2012 and December 2021 were reviewed, and patients with intraoperatively diagnosed FNSs were identified. Clinical data and preoperative imaging were retrospectively reviewed for features suggestive of FNS, and factors associated with good postoperative facial nerve function (House-Brackmann [HB] grade ≤ 2) were identified. A preoperative imaging protocol for suspected VS and recommendations for surgical decision-making following an intraoperative FNS diagnosis were created. RESULTS Nineteen patients (1.3%) with FNSs were identified. All patients had normal facial motor function preoperatively. In 12 patients (63%), preoperative imaging demonstrated no features suggestive of FNS, with the remainder showing subtle enhancement of the geniculate/labyrinthine facial segment, widening/erosion of the fallopian canal, or multiple tumor nodules in retrospect. Eleven (57.9%) of the 19 patients underwent a retrosigmoid craniotomy, and in the remaining patients, a translabyrinthine (n = 6) or transotic (n = 2) approach was used. Following FNS diagnosis, 6 (32%) of the tumors underwent gross-total resection (GTR) and cable nerve grafting, 6 (32%) underwent subtotal resection (STR) and bony decompression of the meatal facial nerve segment, and 7 (36%) underwent bony decompression only. All patients undergoing subtotal debulking or bony decompression exhibited normal postoperative facial function (HB grade I). At the last clinical follow-up, patients who underwent GTR with a facial nerve graft had HB grade III (3 of 6 patients) or IV facial function. Tumor recurrence/regrowth occurred in 3 patients (16%), all of whom had been treated with either bony decompression or STR. CONCLUSIONS Intraoperative diagnosis of an FNS during a presumed VS resection is rare, but its incidence can be reduced further by maintaining a high index of suspicion and undertaking further imaging in patients with atypical clinical or imaging features. If an intraoperative diagnosis does occur, conservative surgical management with bony decompression of the facial nerve only is recommended, unless there is significant mass effect on surrounding structures.

Introduction: It is a rare, but recognised phenomenon that malignant testicular germ cell tumours can ‘burn-out’, where the primary lesion spontaneously regresses and presents with no viable remaining malignant cells leaving only a residual ‘tumour scar’, frequently in the context of distant metastatic disease Case Report: We present a case report of a patient who underwent serial ultrasound scans documenting regression of a testicular lesion from a malignant appearance to a burned-out lesion, where subsequent resection and histology demonstrated features of a completely regressed seminomatous germ cell tumour with no residual viable tumour cells. Discussion: To the best of our knowledge, there are no previously documented cases where a tumour has been longitudinally followed from sonographic features of concern for malignancy to ‘burned-out’ appearances. Spontaneous testicular tumour regression has instead been inferred based on the presence of a ‘burned-out’ testicular lesion in patients presenting with distant metastatic disease. Conclusion: This case provides further evidence supporting the concept of spontaneous testicular germ cell tumour regression. Ultrasound practitioners should be aware of this rare phenomenon in men presenting with metastatic germ cell tumour and, additionally, that this condition may present with acute scrotal pain.

To review the outcomes of cochlear implants (CI) in patients with neurofibromatosis type 2 (NF2) in a large cohort, and identify factors associated with poor hearing benefit.Fifteen-year retrospective national observational case series.United Kingdom regional NF2 multidisciplinary teams.Consecutive patients with NF2 receiving a CI.CI for hearing rehabilitation.1) Audiometric performance at 9 to 12 months after implantation using City University of New York (CUNY) sentence recognition score, and Bamford- Kowal-Bench (BKB) word recognition score in quiet (BKBq), and in noise (BKBn). 2) CI use at most recent review.Sixty four consecutive patients, median age 43 years, were included. Nine to 12 months mean audiometric scores were: CUNY 60.9%, BKBq 45.8%, BKBn 41.6%. There was no difference in audiometric outcomes between VS treatment modalities. At most recent review (median 3.6 years from implantation), 84.9% with device in situ/available data were full or part-time users. Between 9 and 12 months and most recent review there was an interval reduction in mean audiometric scores: CUNY -12.9%, BKBq -3.3%, BKBn -4.9%. Larger tumor size and shorter duration of profound hearing loss were the only variables associated with poorer audiometric scores. Tumor growth at the time of surgery was the only variable associated with CI non-use. Individual patient response was highly variable.CI can provide significant and sustained auditory benefits to patients with NF2 independent of tumor treatment modality, with the majority of those implanted becoming at least part-time users. Larger datasets are required to reliably assess the role of independent variables.

Molecular markers are being applied increasingly to various aspects of tree improvement. This thesis reports two such applications. The first involves tracing the natural origins and assessing the genetic diversity of the Portuguese Landrace of E. globulus, which is a core component of the Portuguese breeding program. In order to achieve this, variation in chloroplast DNA (cpDNA) sequence and microsatellite allele frequency in 47 individuals of the Portuguese Landrace were compared with native stand material. The native gene pool of E. globulus is genetically diverse, with substantial geographically structured genetic variation in molecular markers, which makes it possible to trace the origin of germplasm of unknown pedigree, such as the Portuguese Landrace. Similar affinities suggested by the two independent marker systems provided strong evidence that the Portuguese Landrace was predominantly derived from south-eastern Tasmania and to a lesser extent south-eastern Victoria. Ascertaining the origin of and diversity in such populations will help to avoid inbreeding and will capture the most favourable traits from native populations when they are used in breeding programs. The second application of molecular markers addressed in this thesis involved the construction of a genetic linkage map and searching for molecular markers associated with quantitative trait loci (QTL) in E. globulus. This study focussed on identifying QTL for susceptibility to Mycosphaerella leaf blotch (MLB), a fungal disease affecting the growth of eucalypt plantations worldwide, and other potentially correlated traits. In order to search for QTL, parental and consensus linkage maps were constructed in an F2 inter-provenance cross of Eucalyptus globulus with clonal replication. The consensus map used for QTL detection contained 169 markers (34 SSR and 135 AFLP loci) in 11 linkage groups. The inclusion of SSR markers allowed comparison of linkage and QTL information to other mapping and QTL studies conducted in different mapping pedigrees of E. globulus and other species in the subgenus Symphyomyrtus. The F2 was genetically variable, with significant differences detected between genotypes for all recorded traits. Significant QTL were detected for susceptibility to MLB, herbivory by the autumn gum moth, growth and vegetative phase change. In the case of MLB susceptibility, two major unlinked QTL explained over 70% of the phenotypic variance. This study reports the first QTL affecting height to vegetative phase change and disease resistance in E. globulus. These findings will help to elucidate the genetic control of these complex traits in Eucalyptus, and provide information that will be useful in attempts to incorporate them into breeding programs.

ObjectiveThis study aimed to explore the impact of the coronavirus disease 2019 pandemic and postponement of elective surgical procedures for profoundly deaf patients awaiting cochlear implantation.MethodOpen-ended questionnaires were sent to all adult patients awaiting cochlear implantation surgery. Qualitative analysis was performed using a grounded theory approach.ResultsParticipants described a primarily negative impact on wellbeing from the surgery delay, expressing feelings of isolation or loneliness. Low mood, depression or hopelessness were commonly expressed by elderly participants; frustration and anxiety were described by young adults. Participants described a negative impact on their general daily life, describing difficulties communicating with facemasks and struggles with reliance on telephone communication because of social distancing. Despite these significant psychosocial challenges, only a minority described adaptive coping strategies.DiscussionProfoundly deaf patients may be at greater psychosocial risk because of unique challenges from their hearing disability. Our findings can be used to develop evidence-driven strategies to improve communication, wellbeing and quality of life.

The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications entitled "Incidental Imaging Findings-The Role of Medical Ultrasound." IFs are less commonly encountered in the spleen than in many other abdominal organs but remain a frequent dilemma in clinical practice. A histological diagnosis is rarely necessary for patient management. Many IFs, such as secondary spleens and splenic cysts, are harmless and do not require any further investigation. The diagnosis of many other focal splenic lesions is, however, often problematic. The following overview is intended to illustrate a variety of incidentally detected spleen pathologies such as size variants, shape variants, secondary spleens, focal splenic lesions and splenic calcifications. It should aid the examiner in establishing the diagnosis. Moreover, it should help the ultrasound practitioner decide which pathologies need no further investigation, those requiring interval imaging and cases in which immediate further diagnostic procedures are required.

Objective An operative workflow systematically compartmentalizes operations into hierarchal components of phases, steps, instrument, technique errors, and event errors. Operative workflow provides a foundation for education, training, and understanding of surgical variation. In this Part 2, we present a codified operative workflow for the translabyrinthine approach to vestibular schwannoma resection. Methods A mixed-method consensus process of literature review, small-group Delphi's consensus, followed by a national Delphi's consensus was performed in collaboration with British Skull Base Society (BSBS). Each Delphi's round was repeated until data saturation and over 90% consensus was reached. Results Seventeen consultant skull base surgeons (nine neurosurgeons and eight ENT [ear, nose, and throat]) with median of 13.9 years of experience (interquartile range: 18.1 years) of independent practice participated. There was a 100% response rate across both the Delphi rounds. The translabyrinthine approach had the following five phases and 57 unique steps: Phase 1, approach and exposure; Phase 2, mastoidectomy; Phase 3, internal auditory canal and dural opening; Phase 4, tumor debulking and excision; and Phase 5, closure. Conclusion We present Part 2 of a national, multicenter, consensus-derived, codified operative workflow for the translabyrinthine approach to vestibular schwannomas. The five phases contain the operative, steps, instruments, technique errors, and event errors. The codified translabyrinthine approach presented in this manuscript can serve as foundational research for future work, such as the application of artificial intelligence to vestibular schwannoma resection and comparative surgical research.

Objective The study aimed to determine long-term outcomes in patients with intraoperative electrical conduction block in an anatomically intact facial nerve (FN). Methods Single center retrospective review of prospectively collected database of all vestibular schwannoma surgeries between January 1, 2008 and August 25, 2015. Operative notes were reviewed and patients with anatomically intact FNs, but complete conduction block at the end of surgery were included for analysis. Results In total, 371 patients had vestibular schwannoma surgery of which 18 met inclusion criteria. Mean follow-up was 34.28 months and average tumor size was 28.00 mm. Seventeen patients had House-Brackmann Grade VI facial palsy immediately postoperatively and one patient was grade V. At 1 year, three patients remained grade VI (17%), two improved to grade V (11%), seven to grade IV (39%), six to grade III (33%), and one patient to grade II (6%). On extended follow-up, five patients (28%) had additional 1 to 2 score improvement in facial function. Subset analysis revealed no correlation of tumor size, vascularity, adherence to nerve, operative approach, extent of resection, splaying of FN, and recurrent tumor or sporadic tumors to the extent of FN recovery. Conclusion Intraoperative conduction block does not condemn a patient to permanent FN palsy. There is potential for a degree of recovery comparable with those undergoing nerve grafting. Our data do not clearly support a policy of same-surgery or early-postoperative primary nerve grafting in the event of a complete conduction block, and instead we favor monitoring for recovery in an anatomically intact nerve.

Objective An operative workflow systematically compartmentalizes operations into hierarchal components of phases, steps, instrument, technique errors, and event errors. Operative workflow provides a foundation for education, training, and understanding of surgical variation. In this Part 1, we present a codified operative workflow for the retrosigmoid approach to vestibular schwannoma resection. Methods A mixed-method consensus process of literature review, small-group Delphi's consensus, followed by a national Delphi's consensus, was performed in collaboration with British Skull Base Society (BSBS). Each Delphi's round was repeated until data saturation and over 90% consensus was reached. Results Eighteen consultant skull base surgeons (10 neurosurgeons and 8 ENT [ear, nose, and throat]) with median 17.9 years of experience (interquartile range: 17.5 years) of independent practice participated. There was a 100% response rate across both Delphi's rounds. The operative workflow for the retrosigmoid approach contained three phases and 40 unique steps as follows: phase 1, approach and exposure; phase 2, tumor debulking and excision; phase 3, closure. For the retrosigmoid approach, technique, and event error for each operative step was also described. Conclusion We present Part 1 of a national, multicenter, consensus-derived, codified operative workflow for the retrosigmoid approach to vestibular schwannomas that encompasses phases, steps, instruments, technique errors, and event errors. The codified retrosigmoid approach presented in this manuscript can serve as foundational research for future work, such as operative workflow analysis or neurosurgical simulation and education.

Introduction Vestibular schwannomas (VS) are histologically benign tumors arising from cranial nerve VIII. Far from a homogenous proliferation of Schwann cells, mounting evidence has highlighted the complex nature of the inflammatory microenvironment in these tumors. Methods A review of the literature pertaining to inflammation, inflammatory molecular pathways, and immune-related therapeutic targets in VS was performed. Relevant studies published up to June 2020 were identified based on a literature search in the PubMed and MEDLINE databases and the findings were synthesized into a concise narrative review of the topic. Results The VS microenvironment is characterized by a dense infiltrate of inflammatory cells, particularly macrophages. Significantly higher levels of immune cell infiltration are observed in growing versus static tumors, and there is a demonstrable interplay between inflammation and angiogenesis in growing VS. While further mechanistic studies are required to ascertain the exact role of inflammation in angiogenesis, tumor growth, and Schwann cell control, we are beginning to understand the key molecular pathways driving this inflammatory microenvironment, and how these processes can be monitored and targeted in vivo. Conclusion Observational research has revealed a complex and heterogeneous tumor microenvironment in VS. The functional landscape and roles of macrophages and other immune cells in the VS inflammatory infiltrate are, however, yet to be established. The antiangiogenic drug bevacizumab has shown the efficacy of targeted molecular therapies in VS and there is hope that agents targeting another major component of the VS microenvironment, inflammation, will also find a place in their future management.

Although often asymptomatic and detected incidentally, varicocele is a relatively common problem in patients who seek medical attention for infertility problems. Ultrasound (US) is the imaging modality of choice for evaluation, but there is no consensus on the diagnostic criteria, classification, and examination technique. In view of this uncertainty, the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology (ESUR-SPIWG) undertook a systematic review of the available literature on this topic, to use as the basis for evidence-based guidelines and recommendations. This paper provides the results of the systematic review on which guidelines were constructed.

This study was devised to evaluate the imaging appearances of the interureteric crest (IUC) of the bladder on magnetic resonance imaging (MRI). The primary objective was to determine how commonly the IUC was observed on pelvic MRI examinations. The secondary objectives were to determine the average size of the IUC, its MRI signal characteristics and whether there is variation between men and women. By defining the imaging findings we hope to prevent misinterpretation of normal anatomy on MRI and, therefore, prevent unnecessary further investigations and procedures. We retrospectively reviewed 114 adult patient’s magnetic resonance imaging examinations of the pelvis. Two readers independently recorded information about the presence and characteristics of the IUC with a third reader used to arbitrate in cases of disagreement. The IUC was demonstrated on MRI in 75% of patients. It was best observed on T2w sequences as a continual ridge of low signal intensity between the ureters. The mean AP diameter of the IUC at its mid-point on the sagittal images was 2.4 mm. The IUC is often seen on MRI on T2w images of a non-collapsed bladder. Its characteristic appearance can be used to help the reporting radiologist confidently differentiate identify this normal structure from an area of focal bladder wall thickening that might be misinterpreted as a bladder tumor.

Passive acoustic monitoring of biological soundscapes offers a long-term view into ecosystem state. This is particularly well studied for coral reefs and tropical littoral systems with evidence for similar capability in temperate and deep ocean biologically rich ecosystems. Monitoring ecosystem state under both climate change impacts and changing human usage is a critical piece of understanding how climate change and human use impact ecosystems. Passive acoustics allow for wide area coverage of an ecosystem heartbeat, and changes in key bioacoustic metrics in coral reefs indicate shifts from healthy coral dominated systems to more degraded systems with increased macroalgal cover. These shifts are typically associated with increased ocean temperatures and/or increased human use. The primary controls on coral reef soundscapes are time of day and year. Here, broad comparisons between warmer and cooler years at long term coral reef monitoring sites in Hawaii will be discussed, as well as summer versus winter biological soundscapes at temperate sites in New England. Reef soundscapes encompass contributions from a wide variety of marine flora and fauna, some of which can be identified to species level through characteristic calls and tracked with a high degree of fidelity through passive acoustics alone.

Testicular incidentalomas are non-palpable, asymptomatic lesions, most frequently detected on ultrasound examinations. Each incidentaloma should undergo a standardized diagnostic workup to exclude malignancy and recognize other potentially significant non-malignant conditions that may first present with an incidental finding on scrotal ultrasound. This position statement of the World Federation of Ultrasound in Medicine and Biology (WFUMB) summarizes the available evidence on management of testicular incidentalomas and describes efficient management strategies with particular reference to the role of ultrasound techniques. (C) 2021 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

BackgroundBilateral vestibular schwannomas (VS) are pathognomonic of Neurofibromatosis type 2 (NF2), but the diagnostic criteria also include unilateral vestibular schwannomas (UVS) in combination with multiple meningiomas (MM) and other schwannomas, as well as MM without VS. ObjectiveTo investigate the diagnostic value of these criteria and establish the presence of other genetic conditions in patients presenting in this manner.Methods The (BLINDED FOR REVIEW) NF2 database was accessed to obtain information on patients presenting with a UVS and MM or ≥2 non-intradermal schwannomas (NIDS). We gathered data on patients diagnosed with NF2 due to MM without VS, and on patients presenting with MM without meeting NF2 criteria. Analysis was performed for pathogenic variants (PV) in NF2, SMARCE1, SMARCB1 and LZTR1.Results 131/131 patients presenting with a UVS and MM had a non-refuted diagnosis of NF2 after molecular studies, in comparison with 85/96 patients presenting with UVS and ≥2 NIDS (p=ConclusionPatients presenting with UVS and MM are significantly more likely to have a non-refuted diagnosis of NF2 than patients presenting with UVS and ≥2 NIDS, but significantly less likely to develop bilateral VS. 7% of those presenting with MM without meeting NF2 criteria had PV in SMARCE1, and 5% had mosaic NF2.

PURPOSE: To evaluate the incidence of mosaicism in de novo neurofibromatosis 2 (NF2).METHODS: Patients fulfilling NF2 criteria, but with no known affected family member from a previous generation (n = 1055), were tested for NF2 variants in lymphocyte DNA and where available tumor DNA. The proportion of individuals with a proven or presumed mosaic NF2 variant was assessed and allele frequencies of identified variants evaluated using next-generation sequencing.RESULTS: The rate of proven/presumed mosaicism was 232/1055 (22.0%). However, nonmosaic heterozygous pathogenic variants were only identified in 387/1055 (36.7%). When variant detection rates in second generation nonmosaics were applied to de novo cases, we assessed the overall probable mosaicism rate to be 59.7%. This rate differed by age from 21.7% in those presenting with bilateral vestibular schwannoma CONCLUSION: This study has identified a very high probable mosaicism rate in de novo NF2, probably making NF2 the condition with the highest expressed rate of mosaicism in de novo dominant disease that is nonlethal in heterozygote form. Risks to offspring are small and probably correlate with variant allele frequency detected in blood.

Purpose: We have evaluated deficiencies in existing diagnostic criteria for neurofibromatosis 2 (NF2). Methods: Two large databases of individuals fulfilling NF2 criteria (n=1361) and those tested for NF2 variants with criteria short of diagnosis (n=1416) were interrogated. We assessed the proportions meeting each diagnostic criterion with constitutional or mosaic NF2 variants and the Positive Predictive Value (PPV) with regard to definite diagnosis.Results: There was no evidence for usefulness of old criteria ‘glioma’ or ‘neurofibroma’. ‘Ependymoma’ had 100% PPV and high levels of confirmed NF2 diagnosis (67.7%). Those with bilateral vestibular schwannoma (VS) alone aged ≥60 years had the lowest confirmation rate (6.6%) and reduced PPV(80%). Siblings as a first-degree-relative, without an affected parent, had 0% PPV. All three individuals with unilateral VS and an affected sibling were proven not to have NF2. The biggest overlap was with LZTR1-associated schwannomatosis. In this category, seven individuals with unilateral VS plus ≥2 non-dermal schwannomas reduced PPV to 67%.Conclusion: The present study has confirmed important deficiencies in NF2 diagnostic criteria. The term ‘glioma’ should be dropped and replaced by ‘ependymoma’. Similarly ‘neurofibroma’ should be removed. Dropping ‘sibling’ from first-degree-relatives should be considered and testing of LZTR1 should be recommended for unilateral VS.

Objective Evidence for the management of acute otitis externa (AOE) is limited, with unclear diagnostic criteria and variably reported outcome measures that may not reflect key stakeholder priorities. We aimed to develop 1) a definition, 2) diagnostic criteria and 3) a core outcome set (COS) for AOE. Study design COS development according to Core Outcome Measures in Effectiveness Trials (COMET) methodology and parallel consensus selection of diagnostic criteria/definition. Setting Stakeholders from the United Kingdom. Subjects and methods Comprehensive literature review identified candidate items for the COS, definition and diagnostic criteria. Nine individuals with past AOE generated further patient-centred candidate items. Candidate items were rated for importance by patient and professional (ENT doctors, general practitioners, microbiologists, nurses, audiologists) stakeholders in a three-round online Delphi exercise. Consensus items were grouped to form the COS, diagnostic criteria, and definition. Results Candidate COS items from patients (n = 28) and literature (n = 25) were deduplicated and amalgamated to a final candidate list (n = 46). Patients emphasised quality-of-life and the impact on daily activities/work. Via the Delphi process, stakeholders agreed on 31 candidate items. The final COS covered six outcomes: pain; disease severity; impact on quality-of-life and daily activities; patient satisfaction; treatment-related outcome; and microbiology. 14 candidate diagnostic criteria were identified, 8 reaching inclusion consensus. The final definition for AOE was ‘diffuse inflammation of the ear canal skin of less than 6 weeks duration’. Conclusion The development and adoption of a consensus definition, diagnostic criteria and a COS will help to standardise future research in AOE, facilitating meta-analysis. Consulting former patients throughout development highlighted deficiencies in the outcomes adopted previously, in particular concerning the impact of AOE on daily life.

The superior swimming ability of fish has encouraged the development of fish-like robots. To fully capture fish swimming kinematics a continuum under-actuated robot can be used, and there are many examples of such robots in the literature. But for realistic fish-like swimming in strong currents such robots will benefit from closed-loop feedback. We demonstrate how this can be achieved, underwater, using a stretchy neoprene sensing skin with embedded, discrete dielectric elastomer stretch sensors. The latest prototype skin, with 8 sensors, 4 on each side, is currently being evaluated on an underactuated tensegrity fish-like robot driven by a stepper motor. Carangiform movement of the body has been characterized using cameras and this data has been compared with a virtual model of the robot that uses sensor input for real-time model kinematic data. Four angles along the body defined the shape. A root mean square error between model and true camera angles of less than 3° was calculated for realistic cangiform motion at 0.5 Hz tail frequency.

Detecting acoustic transients by signal-to-noise ratio (SNR) becomes problematic in nonstationary ambient noise environments characteristic of coral reefs. An alternate approach presented here uses signal directionality to automatically detect and localize transient impulsive sounds collected on underwater vector sensors spaced tens of meters apart. The procedure, which does not require precise time synchronization, first constructs time-frequency representations of both the squared acoustic pressure (spectrogram) and dominant directionality of the active intensity (azigram) on each sensor. Within each azigram, sets of time-frequency cells associated with transient energy arriving from a consistent azimuthal sector are identified. Binary image processing techniques then link sets that share similar duration and bandwidth between different sensors, after which the algorithm triangulates the source location. Unlike most passive acoustic detectors, the threshold criterion for this algorithm is bandwidth instead of pressure magnitude. Data collected from shallow coral reef environments demonstrate the algorithm's ability to detect SCUBA bubble plumes and consistent spatial distributions of somniferous fish activity. Analytical estimates and direct evaluations both yield false transient localization rates from 3% to 6% in a coral reef environment. The SNR distribution of localized pulses off Hawaii has a median of 7.7 dB and interquartile range of 7.1 dB.

Background Limited data exist on the disease course of neurofibromatosis type 2 (NF2) to guide clinical trial design. Methods A prospective database of patients meeting NF2 diagnostic criteria, reviewed between 1990 and 2020, was evaluated. Follow-up to first vestibular schwannoma (VS) intervention and death was assessed by univariate analysis and stratified by age at onset, era referred, and inheritance type. Interventions for NF2-related tumors were assessed. Cox regression was performed to determine the relationship between individual factors from time of diagnosis to NF2-related death. Results Three hundred and fifty-three patients were evaluated. During 4643.1 follow-up years from diagnosis to censoring, 60 patients (17.0%) died. The annual mean number of patients undergoing VS surgery or radiotherapy declined, from 4.66 and 1.65, respectively, per 100 NF2 patients in 1990-1999 to 2.11 and 1.01 in 2010-2020, as the number receiving bevacizumab increased (2.51 per 100 NF2 patients in 2010-2020). Five patients stopped bevacizumab to remove growing meningioma or spinal schwannoma. 153/353 (43.3%) had at least one neurosurgical intervention/radiation treatment within 5 years of diagnosis. Patients asymptomatic at diagnosis had longer time to intervention and better survival compared to those presenting with symptoms. Those symptomatically presenting 40 years had poorer overall survival than those presenting at 26-39 years (P = .03 and P = .02, respectively) but those presenting between 16 and 39 had shorter time to VS intervention. Individuals with de novo constitutional variants had worse survival than those with de novo mosaic or inherited disease (P = .004). Conclusion Understanding disease course improves prognostication, allowing for better-informed decisions about care.

Imaging plays a crucial role in the evaluation of scrotal trauma. Among the imaging modalities, greyscale ultrasound and Colour Doppler ultrasound (CDUS) are the primary techniques with the selective utilisation of advanced techniques such as contrast-enhanced ultrasound (CEUS) and elastography. Despite ultrasound being the mainstay of imaging scrotal trauma, its diagnostic performance is not fully established. Considering these difficulties and their impact on clinical practice, the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology (ESUR-SPIWG) established an expert task force to review the current literature and consolidate their expertise on examination standards and imaging appearances of various entities in scrotal trauma. This paper provides the position statements agreed on by the task force with the aim of providing guidance for the use of imaging especially multiparametric US in scrotal trauma. Key Points • Greyscale and Colour Doppler ultrasound are the mainstay of imaging in patients with scrotal trauma. • Contrast-enhanced ultrasound and elastography are the advanced techniques useful as a problem-solving modality in equivocal cases. • This paper summarises the position statements of the ESUR-SPIWG on the appropriate utilisation of multiparametric ultrasound and other imaging modalities in the evaluation of scrotal trauma.

This paper presents a high data-rate underwater acoustic communication system that does not rely on large, powerful, and computationally complex modems. Our small size, weight, and power system is a reconfigurable acoustic modem platform (RAMP) that exploits transducer directivity to reduce the effects of multipath and mutual interference, thus eliminating the need for a traditional channel equalizer. Experimental results are shown to demonstrate the feasibility of RAMP in a shallow-water ocean environment to deliver real-time data transfer.

OBJECTIVE: Electrically evoked auditory brainstem responses (eABRs) can be recorded before cochlear implant (CI) surgery to verify auditory nerve function, and is particularly helpful in to assess the function of the auditory nerve in cases of auditory nerve hypoplasia. This is the first study to compare three preimplant eABRs recording techniques: 1) standard extracochlear, 2) novel intracochlear, and 3) conventional intracochlear with the CI. STUDY DESIGN: A within-participants design was used where eABRs were sequentially measured during CI surgery using three methods with stimulation from: 1) an extracochlear electrode placed at the round window niche, 2) two different electrodes on a recently developed Intracochlear Test Array (ITA), and 3) two different electrodes on a CI electrode array. SETTING: New adults implantees (n = 16) were recruited through the Manchester Auditory Implant Centre and eABR measurements were made in theater at the time of CI surgery. PATIENTS: All participants met the clinical criteria for cochlear implantation. Only participants with radiologically normal auditory nerves were recruited to the study. All participants were surgically listed for either a MED-EL Synchrony implant or a Cochlear Nucleus Profile implant, per standard practice in the implant centre. OUTCOME MEASURES: Primary outcome measures were: 1) charge (μC) required to elicit a threshold response, and 2) latencies (ms) in the threshold waveforms. Secondary outcome measures were: 1) morphologies of responses at suprathreshold stimulation levels and 2) wave V growth patterns. RESULTS: eABRs were successfully measured from 15 participants. In terms of primary outcome measures, the charge required to elicit a response using the extracochlear electrode (median = 0.075 μC) was approximately six times larger than all other electrodes and the latency of wave V was approximately 0.5 ms longer when using the extracochlear electrode (mean = 5.1 ms). In terms of secondary outcomes, there were some minor quantitative differences in responses between extracochlear and intracochlear stimulation; in particular, ITA responses were highly variable in quality. The ITA responses were rated poor quality in 33% of recordings and in two instances did not allow for data collection. When not disrupted by open circuits, the median ITA response contained one more waveform than the median extracochlear response. CONCLUSIONS: In this first study comparing intracochlear and extracochlear stimulation, the results show that both can be used to produce an eABR that is representative of the one elicited by the CI. In the majority of cases, extracochlear stimulation was the preferred approach for preimplant auditory nerve function testing because of consistency, recordings that could be analyzed, and because extracochlear placement of the electrode does not require a cochleostomy to insert an electrode.

Introduction: Standardized outcome measures are importantfor accurately monitoring the language development of pre-lingually deaf children receiving auditory implants. Current commonly used outcome measures are time-consuming,limiting the practicality of regular testing. To address these limitations, the Manchester Spoken Language Development Scale (MSLDS) was developed as a quick and easily applicable interim measurement. This is an 11-point scale designed to provide a streamlined overview of a child's expressive language development. This study describes the MSLDS, evaluates its ease of use and inter-rater reliability, and outlines its application in the paediatric auditory implant population. Methods: Sixteen speech therapists and teachers for the deaf reviewed videos of paediatric cochlear implant assessmentsand rehabilitation sessions at a UK auditory implant centre. Twenty-five videos from fourteen children were used in this validation study. Reviewers were asked to evaluate a child's language development using the MSLDS by assigning a score for each video and to evaluate the ease of use of the scale. Each video wasrated by three different reviewers. Results: MSLDS scores showed a high degree of consistency between raters for each child. 8/25 (32%) videos demonstrated perfect agreement on the MSLDS. In 15/25 (60%) videos, there was a one-point difference between MSLDS scores. The remaining 2/25 (8%) videos varied by 2 points. Statistical analysis demonstrated an intra-class correlation coefficient (ICC) of 0.987, indicating a high level of agreement between users of the scale. Qualitative feedback from the raters suggested further modifications which have been incorporated into the scale. Conclusion: The high inter-rater agreement reflects the potential for the MSLDS to be a reliable tool for monitoring language development in the paediatric auditory implant population.

ObjectivesCases of sporadic vestibular schwannoma (sVS) have a low rate of association with germline pathogenic variants. However, some individuals with sVS can represent undetected cases of neurofibromatosis type 2 (NF2) or schwannomatosis. Earlier identification of patients with these syndromes can facilitate more accurate familial risk prediction and prognosis.MethodsCases of sVS were ascertained from a local register at the Manchester Centre for Genomic Medicine. Genetic analysis was conducted in NF2 on blood samples for all patients, and tumour DNA samples when available. LZTR1 and SMARCB1 screening was also performed in patient subgroups.ResultsAge at genetic testing for vestibular schwannoma (VS) presentation was younger in comparison with previous literature, a bias resulting from updated genetic testing recommendations. Mosaic or constitutional germline NF2 variants were confirmed in 2% of patients. Pathogenic germline variants in LZTR1 were found in 3% of all tested patients, with a higher rate of 5% in patients SMARCB1 variants were identified within the cohort. Considering all individuals who received tumour DNA analysis, 69% of patients were found to possess two somatic pathogenic NF2 variants, including those with germline LZTR1 pathogenic variants.ConclusionsUndiagnosed schwannoma predisposition may account for a significant minority of apparently sVS cases, especially at lower presentation ages. Loss of NF2 function is a common event in VS tumours and may represent a targetable common pathway in VS tumourigenesis. These data also support the multi-hit mechanism of LZTR1-associated VS tumourigenesis.

Biologically complex coastal environments, such as coral reefs, demonstrate an equally rich ambient soundscape. Bioacoustic features of coastal soundscapes are closely tied with relative ecosystem health, functional groups present, and can be linked with specific behaviors. Biological contributions to ambient soundscapes have distinctive qualities as compared to sound associated with physical processes (i.e. wind and wave noise). While some biological components are readily identifiable, such as marine mammal or fish calls, the background noise associated with hundreds of thousands of biological clicks, snaps, and pops is not as well studied but contains a wealth of information about the ecosystem. A 64-element line array with 4.5 kHz design frequency was deployed for several field experiments off the coast of Kona, Hawaii in 2019 and 2020. Soundscape data from Hawaii were compared with comparable omnidirectional time series from Bermuda (2020) and coastal New England rocky reefs (2020–2021). Similarities in certain spectral features associated with biological sound sources were found between these unique ecosystems. The characteristic coral reef evening chorus, or significant increase in sound levels immediately prior to sunset, was consistent in Hawaii and Bermuda with comparable crepuscular changes in coastal New England.

Climate change impacts and mitigation strategies will define our interaction with the oceans this century. Marine carbon sequestration could facilitate the enormous scaling necessary for gigaton-level carbon dioxide (CO2) removal: at least 10 GT/y by 2050 and 20 GT/y by 2100, required just to limit anthropogenic warming to below 2°C. Many proposed marine CO2 removal techniques involve the distributed capture of carbon, i.e., accelerating the biological carbon pump (e.g., iron ocean fertilization or artificial upwelling) or shifting the dissolution equilibrium of CO2 (e.g., ocean alkalinity enhancement). However, technology that enables rapid, inexpensive, persistent and accurate measurement and validation of drawn-down CO2 at the sequestration time- and regional ocean spatial-scales necessary to quantify carbon capture does not exist today. The accuracy and wholeness of these future techniques will be important for assigning financial value to marine CO2 removal processes in a carbon market, as well as enabling thorough evaluation of environmental impacts and a comprehensive understanding of ocean carbon dynamics. I will discuss ARPA-E’s interest in carbon sensing approaches, including passive and active acoustic techniques, which could rapidly quantify ocean carbon flux at scale and introduce powerful tools to address the challenges of mitigating climate impacts at sea.

ObjectivesSchwannomatosis is a dominantly inherited condition predisposing to schwannomas of mainly spinal and peripheral nerves with some diagnostic overlap with neurofibromatosis-2 (NF2), but the underlying epidemiology is poorly understood. We present the birth incidence and prevalence allowing for overlap with NF2.MethodsSchwannomatosis and NF2 cases were ascertained from the Manchester region of England (population=4.8 million) and from across the UK. Point prevalence and birth incidence were calculated from regional birth statistics. Genetic analysis was also performed on NF2, LZTR1 and SMARCB1 on blood and tumour DNA samples when available.ResultsRegional prevalence for schwannomatosis and NF2 were 1 in 126 315 and 50 500, respectively, with calculated birth incidences of 1 in 68 956 and 1 in 27 956. Mosaic NF2 causes a substantial overlap with schwannomatosis resulting in the misdiagnosis of at least 9% of schwannomatosis cases. LZTR1-associated schwannomatosis also causes a small number of cases that are misdiagnosed with NF2 (1%–2%), due to the occurrence of a unilateral vestibular schwannoma. Patients with schwannomatosis had lower numbers of non-vestibular cranial schwannomas, but more peripheral and spinal nerve schwannomas with pain as a predominant presenting symptom. Life expectancy was significantly better in schwannomatosis (mean age at death 76.9) compared with NF2 (mean age at death 66.2; p=0.004).ConclusionsWithin the highly ascertained North-West England population, schwannomatosis has less than half the birth incidence and prevalence of NF2.

The updated version of the EFSUMB guidelines on the application of non-hepatic contrast-enhanced ultrasound (CEUS) deals with the use of microbubble ultrasound contrast outside the liver in the many established and emerging applications.Die aktualisierte Version der EFSUMB-Leitlinien für die Anwendung von nicht-hepatischem kontrastverstärktem Ultraschall (CEUS) befasst sich mit der Verwendung von Mikrobläschen Ultraschall-Kontrastmitteln außerhalb der Leber in zahlreichen etablierten und neu entstehenden Einsatzbereichen.

The authors present the case of a 24-year-old female with neurofibromatosis type 2. Growth of the left vestibular schwannoma and progressive hearing loss prompted the decision to proceed to translabyrinthine resection with cochlear nerve preservation and cochlear implant insertion. Complete resection with preservation of the facial and cochlear nerves was achieved. The patient had grade 1 facial function and was discharged on postoperative day 4 following suturing of a minor CSF leak. This case highlights the feasibility of cochlear nerve preservation and cochlear implant insertion in appropriately selected patients, offering a combination of effective tumor control and hearing rehabilitation. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21122

Background It is common for patients with neurofibromatosis type 2 to develop bilateral profound hearing loss hearing loss, and this is one of the main determinants of quality of life in this patient group. Objectives The aim of this systematic review was to review the current literature regarding hearing outcomes of treatments for vestibular schwannomas in neurofibromatosis type 2 including conservative and medical management, radiotherapy, hearing preservation surgery and auditory implantation in order to determine the most effective way of preserving or rehabilitating hearing. Search strategy A MESH search in PubMed using search terms (('Neurofibromatosis 2' [Mesh]) AND 'Neuroma, Acoustic'[Mesh]) AND 'Hearing Loss' [Mesh] was performed. A search using keywords was also performed. Studies with adequate hearing outcome data were included. With the exception of the cochlear implant studies (cohort size was very small), case studies were excluded. Evaluation method The GRADE system was used to assess quality of publication. Formal statistical analysis of data was not performed because of very heterogenous data reporting. Results Conservative management offers the best chance of hearing preservation in stable tumours. The use of bevacizumab probably improves the likelihood of hearing preservation in growing tumours in the short term and is probably more effective than hearing preservation surgery and radiotherapy in preserving hearing. Of the hearing preservation interventions, hearing preservation surgery probably offers better hearing preservation rates than radiotherapy for small tumours but recurrence rates for hearing preservation surgery were high. For patients with profound hearing loss, cochlear implantation provides significantly better auditory outcomes than auditory brainstem implantation. Patients with untreated stable tumours are likely to achieve the best outcomes from cochlear implantation. Those who have had their tumours treated with surgery or radiotherapy do not gain as much benefit from cochlear implantation than those with untreated tumours. Conclusions This review summarises the current literature related to hearing preservation/rehabilitation in patients with NF2. Whilst it provides indicative data, the quality of the data was low and should be interpreted with care. It is also important to consider that the management of vestibular schwannomas in NF2 is complex and decision-making is determined by many factors, not just the need to preserve hearing.

Splenosis is an unusual condition representing auto-transplantation of splenic tissue following splenic trauma or surgery. When detected on imaging studies, the splenosis deposits are usually misinterpreted as pathological masses. We present a case where a pelvic mass incidentally visualized on an MRI examination, was proven to represent a deposit of splenosis by contrast enhanced ultrasound (CEUS). CEUS demonstrated persistent late-phase enhancement characteristic of splenic tissue. Ultrasound practitioners should be aware of this condition when an unusual abdominal or pelvic mass is encountered in a patient with a history of splenic trauma or surgery. CEUS is ideally suited to confirming the diagnosis.

OBJECTIVE Inflammation and angiogenesis may play a role in the growth of sporadic and neurofibromatosis type 2 (NF2)–related vestibular schwannoma (VS). The similarities in microvascular and inflammatory microenvironment have not been investigated. The authors sought to compare the tumor microenvironment (TME) in sporadic and NF2-related VSs using a combined imaging and tissue analysis approach. METHODS Diffusion MRI and high-temporal-resolution dynamic contrast-enhanced (DCE) MRI data sets were prospectively acquired in 20 NF2-related and 24 size-matched sporadic VSs. Diffusion metrics (mean diffusivity, fractional anisotropy) and DCE-MRI–derived microvascular biomarkers (transfer constant [Ktrans], fractional plasma volume, tissue extravascular-extracellular space [ve], longitudinal relaxation rate, tumoral blood flow) were compared across both VS groups, and regression analysis was used to evaluate the effect of tumor size, pretreatment tumor growth rate, and tumor NF2 status (sporadic vs NF2-related) on each imaging parameter. Tissues from 17 imaged sporadic VSs and a separate cohort of 12 NF2-related VSs were examined with immunohistochemistry markers for vessels (CD31), vessel permeability (fibrinogen), and macrophage density (Iba1). The expression of vascular endothelial growth factor (VEGF) and VEGF receptor 1 was evaluated using immunohistochemistry, Western blotting, and double immunofluorescence. RESULTS Imaging data demonstrated that DCE-MRI–derived microvascular characteristics were similar in sporadic and NF2-related VSs. Ktrans (p < 0.001), ve (p ≤ 0.004), and tumoral free water content (p ≤ 0.003) increased with increasing tumor size and pretreatment tumor growth rate. Regression analysis demonstrated that with the exception of mean diffusivity (p < 0.001), NF2 status had no statistically significant effect on any of the imaging parameters or the observed relationship between the imaging parameters and tumor size (p > 0.05). Tissue analysis confirmed the imaging metrics among resected sporadic VSs and demonstrated that across all VSs studied, there was a close association between vascularity and Iba1+ macrophage density (r = 0.55, p = 0.002). VEGF was expressed by Iba1+ macrophages. CONCLUSIONS The authors present the first in vivo comparative study of microvascular and inflammatory characteristics in sporadic and NF2-related VSs. The imaging and tissue analysis results indicate that inflammation is a key contributor to TME and should be viewed as a therapeutic target in both VS groups.

To evaluate the incidence of mosaicism in de novo neurofibromatosis 2 (NF2).Patients fulfilling NF2 criteria, but with no known affected family member from a previous generation (n = 1055), were tested for NF2 variants in lymphocyte DNA and where available tumor DNA. The proportion of individuals with a proven or presumed mosaic NF2 variant was assessed and allele frequencies of identified variants evaluated using next-generation sequencing.The rate of proven/presumed mosaicism was 232/1055 (22.0%). However, nonmosaic heterozygous pathogenic variants were only identified in 387/1055 (36.7%). When variant detection rates in second generation nonmosaics were applied to de novo cases, we assessed the overall probable mosaicism rate to be 59.7%. This rate differed by age from 21.7% in those presenting with bilateral vestibular schwannoma20 years to 80.7% in those aged ≥60 years. A mosaic variant was detected in all parents of affected children with a single-nucleotide pathogenic NF2 variant.This study has identified a very high probable mosaicism rate in de novo NF2, probably making NF2 the condition with the highest expressed rate of mosaicism in de novo dominant disease that is nonlethal in heterozygote form. Risks to offspring are small and probably correlate with variant allele frequency detected in blood.

To assess the compliance with cochlear implantation (CI) in children subsequently diagnosed with autism spectrum disorder (ASD).This was a retrospective case review and survey performed at a tertiary referral centre. Children meeting the criteria for CI who were implanted between 1989 and 2015 and who subsequently received a diagnosis of ASD were included. The primary outcome measure was to assess compliance with CI in children subsequently diagnosed with ASD. Secondary outcome measures included assessment of pre-CI risk factors that may have identified children at higher risk of a subsequent diagnosis of ASD, as well as the benefit obtained by these children following CI.1050 children were implanted between 1989 and 2015. Of these, 22 children were diagnosed with ASD after receiving their CI. The average age at implantation was 2.6 years (median 3, range 1-8 years). The average age for diagnosis of ASD was 5 years, approximately 2 years (median 22 months, range 2-85 months) following CI. Of these, 16/22 (712.7%) regularly use their CI. 6/22 (27.2%) children became non-users of their implant. Some degree of verbal communication was used by 13/22 (59%) of our studied group.There is a range of level of disabilities in ASD, with some relatively minor social communication difficulties through to severe language, cognitive, and behavioural difficulties. Compliance with CI is variable and appears to correlate with the severity of the ASD. Preoperative counselling should include information about the possible impact of later diagnosed disabilities such as ASD on performance.

7th IEEE Asia-Pacific Conference on Applied Electromagnetics, APACE 2016 -- 11 December 2016 through 13 December 2016 -- 127632 ‘Second Consensus Meeting on Management of Complex Inner Ear Malformations: Long Term Results of ABI in Children and Decision Making Between CI and ABI’ took place on 5–6 April 2013 in Kyrenia, Northern Cyprus with the participation of 20 centers from 11 countries. These centers presented their auditory brainstem implantation (ABI) experience in children and infants and also provided the selection criteria and cochlear implant (CI) results in patients with an abnormal cochlea and nerve. In addition, Cochlear and Med El companies provided presentations regarding solutions to problems during revision surgery and future projections of device technology. According to the results from different centers, it was evident that an ABI is capable of providing hearing sensation in prelingually deafened children with complex inner ear malformations and diseases. It is possible to obtain a pure tone average with an ABI between 30 and 60 dB HL in most of these patients. It has been observed that the majority of children obtain Categories of Auditory Performance (CAP) scores around 5, but occasionally certain ABI users obtained scores of up to CAP 8-II, NEAP-Nottingham Early Assessment Package. The Ear Foundation 2009). CAP scores tend to increase with earlier implantation, i.e. under 2 years of age. However, after 3 years of use, it usually reaches a plateau. Children with additional disorders cannot reach CAP scores of children without disorders. However, they obtain an improvement of cognitive functions but duration of ABI use and increasing chronological age also play a role in this improvement.

Aim The aim of the study was to evaluate whether the twinkle artefact is a valuable feature in the sonographic diagnosis of superficial epidermoid cysts. Materials and methods A retrospective search was undertaken of our institution’s Radiology Information System and pathology database to identify cases of superficial masses showing the twinkle artefact that proceeded to surgical excision. Results Eighteen superficial masses demonstrating the twinkle artefact were identified that were submitted for pathological analysis. Of these, 17 were confirmed to represent epidermoid cysts and only 1 case had an alternative diagnosis (proliferating trichilemmal cyst). Conclusion The presence of the twinkle artefact appears to be a specific and valuable ancillary sonographic feature for the diagnosis of superficial epidermoid cysts.

The aim of this study was to quantify the benefit gained from cochlear implantation in pre- or peri-lingually deafened patients who were implanted as adults Methods: This was a retrospective case-control study. Auditory (BKB/CUNY/3AFC/Environmental sounds), quality of life (GBI/HUI3) and cognitive (customized questionnaire) outcomes in 26 late implanted pre- or peri-lingually deafened adults were compared to those of 30 matched post-lingually deafened, traditional cochlear implant users.There was a statistically significant improvement in all scores in the study group following cochlear implantation. BKB scores for cases was 49.8% compared to 83.6% for controls (p=0.037). CUNY scores for cases was 61.7% compared to 90.3% for controls (p=0.022). The 3AFC and environmental sounds scores were also better in controls compared to cases but the difference was not statistically significant. Quality of life scores improved following implantation in cases and controls but the improvement was only statistically significant in the controls. There was a 7.7% non-user rate in the cases. There were no non-users in the control group.Early deafened,,late implanted patients can benefit audiologically from cochlear implantation and in this study the improvement in speech discrimination scores was greater than expected perhaps reflecting careful selection of patients. Nevertheless, audiological benefits are limited compared to traditional cochlear implant recipients with the implant acting as an aid to lip reading in most cases.With careful selection of candidates, cochlear implantation is beneficial in early deafened, late implanted patients.

An algorithm is presented for automatically localizing transient impulsive sounds collected on several autonomous underwater vector sensors, spaced 15 to 23 m apart. The procedure, which does not require precise time synchronization, exploits transient signals of interest arriving from different azimuthal directions on each sensor. For each sensor the method first constructs time-frequency representations of both the squared acoustic pressure (spectrogram) and dominant directionality of the active intensity (azigram). Within each azigram sets of time-frequency cells associated with transient energy arriving from a consistent azimuthal sector are identified. Standard image processing techniques then link sets that share similar duration and bandwidth between different sensors, after which the algorithm triangulates the source location using the azimuths associated with the detection set. Data collected from shallow coral reef environments demonstrate the algorithm's ability to detect SCUBA bubble plumes and humpback whale song, and reveal consistent spatial distributions of somniferous fish activity. Analytical estimates and direct evaluations both yield false transient localization rates of 3%–6% in the coral reef environment. Many localized pulses have low signal-to-noise ratios, whose distribution has a median of 7.7 dB and an IQR of 7.1 dB. [Work sponsored by DARPA PALS.]

Acoustic transmission loss was measured as a function of range on a coral reef to better understand the propagation environment at frequencies of 0.5, 2, 5, 10, and 15 kHz. Low-level signals were projected on two contrasting coral reef sites in Hawaii, and received by a hydrophone at ranges up to 500 m. A suite of transmission loss models are tested against the field data. Geoacoustic inversion methods are used to obtain a spreading and attenuation coefficient for each site. This work challenges conventional geometric spreading models in a coral reef setting and quantifies site-specific spreading and attenuation. This work is DISTRIBUTION A. Approved for public release: distribution unlimited. This research was developed with funding from the Defense Advanced Research Projects Agency. The views, opinions and/or findings expressed are those of the author and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government.