bluuebunny/crossref_metadata_2025 huggingface dataset:
EXTRA CRANIAL ARTERIOVENOUS MALFORMATIONS PRESENTING AS PULSATILE TINNITUS
Authors: Yardley M P J , Knight L C
Published: April 2023

We present two cases of extra cranial arteriovenous malformations, which presented as pulsatile tinnitus. They were originally diagnosed by clinical examination and both lesions were subsequently confirmed by angiography and their feeding vessels defined. One case was managed by surgical excision, which produced relief of symptoms. The diagnosis and management of arteriovenous malformations is discussed.
ASSESSMENT OF REVERSIBILITY IN PATIENTS WITH CHRONIC AIRFLOW OBSTRUCTION
Authors: Barros M J , Rees P J
Published: April 2023

Reversibility of airflow obstruction was considered for many years to be a hallmark of asthma. It is now clear that many patients with chronic airflow obstruction, often labelled as chronic obstructive airways disease or chronic bronchitis and emphysema, show some bronchodilation following various drugs.1 At present there is no clinical or physiological factor which reliably predicts the bronchodilator response of such patients to a given medication,2,3 and individual testing of these drugs is necessary. However, the literature on bronchodilator responses in chronic airflow obstruction is confused. There are differences in the selection of patients, the tests used and the interpretation of the results. The aim of this review is to highlight the main problems found when measuring reversibility in such patients, the different factors that influence the reversibility testing and the biases which may confound the interpretation of the results.
A PRESENTATION OF ANAPLASTIC CARCINOMA OF THE THYROID WITH SYMPTOMATIC INTRA‐ABDOMINAL METASTASES
Authors: Lip G Y H , Jaap A J , McCruden D C
Published: April 2023

Anaplastic thyroid carcinoma usually presents with symptoms related to local invasion and compression of structures in the neck. We report a patient with intra‐abdominal metastases presenting with symptoms suggestive of local gastrointestinal disease. Abdominal CT scan and initial laparotomy findings were suggestive of an abdominal aortic aneurysm.
LONG‐TERM SURVIVAL OF A PATIENT WITH MALIGNANT LYMPHOMA OF BONE
Authors: Shewring D J , Addis B J , Carvell J E
Published: April 2023

Malignant lymphoma of bone is an uncommon tumour. A number of studies have outlined the clinicopathological findings and overall favourable prognosis in adults.1,2,3 We report on a woman whose tumour was originally diagnosed as a secondary carcinoma of the upper femur. Twenty‐three years later following proximal femoral replacement, the original histology was reviewed using immunohistochemical techniques and revised to B‐cell malignant lymphoma of bone.
DRESSLER'S SYNDROME PRESENTING AS ACUTE PNEUMONITIS
Authors: Gallen I W , Johnston I D A , Tattersall R B
Published: April 2023

An elderly man developed acute pneumonitis three weeks after a myocardial infarction treated with streptokinase. The differential diagnoses are discussed and a short review of lung disease in the post‐myocardial infarction syndrome is presented.
SPLENIC ABSCESS: IS CONSERVATION APPLICABLE?
Authors: Akoh J A , Auld C D
Published: April 2023

A rare occurrence of salmonella abscess in a congenital cyst of the spleen is presented. Although splenectomy was curative, the role of splenic salvage is discussed. Percutaneous drainage is curative in about 70% of cases and may be the treatment of choice in solitary thick‐walled abscesses. It should be remembered, however, that residual or regenerated splenic tissue is no absolute guarantee against sepsis. The treatment of splenic abscess should be individualised.
STERNO‐COSTO‐CLAVICULAR HYPEROSTOSIS
Authors: Taylor H G , Dawes P T
Published: April 2023

Sterno‐costo‐clavicular hyperostosis (SCCH) is a condition of unknown aetiology in which a chronic inflammatory osteitis affects predominantly the medial clavicle, sternum and distal tibia and femur, sometimes associated with skin disease. We report on two patients with the typical bony lesions of SCCH and no associated skin disease.
ASSESSMENT OF PATIENTS' KNOWLEDGE ABOUT THEIR ILLNESS AND TREATMENT
Authors: Radhamanohar M , Than M , Rizvi S
Published: April 2023

One hundred and twenty two patients over the age of 65 were questioned about their knowledge of their illness and treatment. They were unaware of a quarter of both their illnesses and medications. There was a considerable lack of knowledge about certain groups of diseases and medications, while patients were much better informed about others. The possible reasons for this discrepancy are briefly discussed and some practical suggestions are put forward.
AN UNUSUAL CAUSE FOR RESPIRATORY DIFFICULTY AFTER THYROIDECTOMY
Authors: Krishnan H , May R E
Published: April 2023

Problems with breathing immediately after extubation following thyroidectomy are rare, but can usually be attributed to a surgical error such as damage to one or both recurrent laryngeal nerves. Tracheomalacia may also cause respiratory distress following extubation. We present an unusual cause of failure to resume spontaneous respiration after thyroidectomy.
ISOLATED DUODENAL VARICES AS A CAUSE OF MASSIVE GASTROINTESTINAL BLEEDING
Authors: Brown J N , Cooper J C
Published: April 2023

Portal hypertension and the development of varices in areas of portosystemic venous anastomoses can lead to dramatic and life‐threatening haemorrhage. Varices most commonly occur in the gastro‐oesophageal region but ectopic varices can arise at other sites in the gastrointestinal tract. This report describes a patient with massive haemorrhage from duodenal varices. We believe the case highlights the importance of considering ectopic varices as a cause of gastro‐intestinal haemorrhage especially when oesophageal varices are absent.
THE EFFICACY AND SEDATIVE PROFILE OF ASTEMIZOLE AND CETIRIZINE IN THE TREATMENT OF GRASS POLLEN HAYFEVER IN GENERAL PRACTICE
Authors: Harcup J W , Hawkes G , Saul P A
Published: April 2023

The antihistamines astemizole and cetirizine were compared for the treatment of grass pollen hayfever in 158 patients who received either astemizole (10 mg od) or cetirizine (10 mg od) for a four week period in a randomised double‐blind, double‐dummy, parallel group, comparative assessment.

Patients visited their general practitioner (GP) on three occasions and at each visit the GP made an assessment of the severity of individual hayfever symptoms. Patients recorded daily throughout the study the severity of their hayfever symptoms and their level of daytime sedation on visual analogue scales in a diary card. The primary measure of efficacy was the overall symptom visual analogue scores recorded daily by the patients.

The results demonstrate that these two antihistamines are equally effective treatments for hayfever, in terms of magnitude of symptom relief, speed of onset of symptom improvement and lack of sedative effect.
AN UNUSUAL PRESENTATION OF BILATERAL TUBAL ECTOPIC PREGNANCY
Authors: Erian M , McLaren G R
Published: April 2023

The diagnosis of ectopic pregnancy is sometimes difficult on clinical grounds because of the varied presentation. The clinical triad of amenorrhoea, abnormal vaginal bleeding and lower abdominal pain often raises the suspicion of the diagnosis. There are, however, instances where one or other feature of the triad may be absent.

The present case report illustrates an example of bilateral tubal ectopic pregnancies presenting without amenorrhoea. In this case the presentation was similar to an acute gastrointestinal problem.
Anisotropy free energy contribution of the ferroelectric domain dynamics in PMN‐PT and PIN‐PMN‐PT relaxor ferroelectrics
Authors: Pérez‐Moyet Richard , Cardona‐Quintero Yenny , Doyle Ian M. , Heitmann Adam A.
Published: April 2023

A direct correlation between the materials property behavior with its associated ferroelectric domain mechanisms and the anisotropic component of the Landau free energy is established for binary PMN‐PT (generation I) and ternary PIN‐PMN‐PT (generation II) relaxor ferroelectric single crystal material systems. In addition to their trade‐off in material properties, the observed ferroelectric domain dynamic and the determined free energy anisotropies, especially as approaching phase transition, provide direct insights into the materials field‐dependent behavior between the binary and ternary ferroelectric systems. Domain configuration features such as lamellar structures in binary PMN‐PT and concentric oval‐like structures in ternary PIN‐PMN‐PT result in different material responses to external stimuli. Compared to binary PMN‐PT, the concentric oval‐like domain structures of ternary PIN‐PMN‐PT result in a 20°C higher temperature range of field‐dependent linear behavior, 40% increase in coercive electric field higher elastic stiffness during ferroelectric domain switching, and lower electromechanical energy losses. Separation of the isotropic and anisotropic components in the Landau free energy reveals a higher anisotropic free energy contribution from the ternary system, especially at temperature for practical applications. The high anisotropic free energy found in the ternary PIN‐PMN‐PT system implies that the concentric oval‐like domain structure contributes to reduced electromechanical energy losses and enhanced stability under external applied fields.
Parents Plus parenting programme for parents of adolescents with intellectual disabilities: A cluster randomised controlled trial
Authors: McMahon Suzanne M. , Wilson Charlotte E. , Sharry John
Published: April 2023

Objective

This study evaluated the effectiveness of the Parents Plus Special Needs (PPSN) programme, a seven‐week parenting group intervention for parents of adolescents with intellectual disabilities.

Method

In a cluster randomised controlled trial, 24 intellectual disability services supporting families of adolescents with an intellectual disability were assigned to PPSN (12 services; 141 parents) or waitlist control group (12 services; 136 parents). Primary outcomes were parent‐reported parenting practices, family adjustment, problem behaviours, emotional problems, and prosocial behaviours. Secondary outcomes were parental satisfaction, parental self‐efficacy, and goal attainment.

Results

Compared to the waitlist group, participants in the PPSN group reported improvements in parenting practices, problem behaviours, parental satisfaction, parental self‐efficacy and goal attainment, which were retained at 3‐month follow‐up. There were additional gains for family adjustment at follow‐up.

Conclusion

The PPSN is effective in improving parenting behaviour, family relationships, and problem behaviours in adolescents, but not in improving emotional difficulties.
Damage and recovery of the intrinsic and extrinsic foot muscles from running a full marathon
Authors: Fukano Mako , Nakagawa Kento , Higashihara Ayako , Inami Takayuki , Narita Takaya
Published: April 2023

Purpose

To investigate the effects of full marathon running on intrinsic and extrinsic foot muscle damage and to determine the relationship with the height change of the longitudinal foot arch following full marathon completion.

Methods

Magnetic resonance imaging‐measured transverse relaxation time (T2) of the abductor hallucis (ABH), flexor digitorum brevis (FDB) and quadratus plantae (QP), flexor digitorum longus (FDL), tibialis posterior (TP), and flexor hallucis longus (FHL) from 22 collegiate runners were assessed before and 1, 3, and 8 days after full marathon running. The three‐dimensional foot posture of 10 of the 22 runners was further obtained using a foot scanner system before and 1, 3, and 8 days after the marathon.

Results

Marathon‐induced increases in T2 were observed in the QP, FDL, TP, and FHL 1 day after the marathon (+7.5%, +4.7%, +6.7%, and +5.9%, respectively), with the increased T2 of TP persisting until 3 days after the marathon (+4.6%). T2 changes of FDL and FHL from pre‐marathon to DAY 1 showed direct correlations with the corresponding change in the arch height ratio (r = 0.823, p = 0.003, and r = 0.658, p = 0.038).

Conclusion

The damage and recovery response from a full marathon differed among muscles; QP, FDL, TP, and FHL increased T2 after the marathon, whereas ABH and FDB did not. In addition, T2 changes in FDL and FHL and the arch height ratio change were correlated. Our results suggest that the extrinsic foot muscles could be more susceptible to damage than the intrinsic during marathon running.
Efficacy of short‐term combination of intralymphatic allergen immunotherapy and lokivetmab treatment in canine atopic dermatitis: A double‐blinded, controlled, randomised study
Authors: van Amersfort Kelly , Vernooij Johannes C. M. , van der Lee Annette
Published: April 2023

Background

Allergen‐specific immunotherapy (ASIT) is an effective therapy for canine atopic dermatitis (cAD). Intralymphatic immunotherapy (ILIT) is potentially beneficial in decreasing time to clinical effectiveness.

Objective

To compare clinical efficacy of six monthly ILIT injections combined with three monthly injections of lokivetmab (LVM) with monthly LVM monotherapy at Day (D)168. To monitor dogs treated with ILIT for an additional six months of subcutaneous immunotherapy (SCIT).

Animals

Thirty‐six client‐owned dogs with cAD.

Materials and Methods

In this double‐blinded, randomised study, dogs received either six monthly injections of ILIT combined with three monthly LVM injections (ILIT group) or six monthly LVM injections (LVM group). Monthly evaluations with pruritus Visual Analogue Scale (pVAS), Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI‐04) and medication scores (MS) were undertaken. Owners completed a Quality of Life (QoL) questionnaire. Treatment success was predefined as ≥50% reduction in pVAS and CADESI‐04 score ≤ 10. After D168, the ILIT group continued with SCIT until subjective assessment at 12 months.

Results

The treatment benchmark at D168 was achieved by 11.1% of the ILIT group and 11.8% of LVM group. A significant decrease in mean pVAS and CADESI scores was observed in both groups (p < 0.001). The ILIT group had a trend towards higher MS compared to LVM. QoL was better in LVM (p = 0.01). At 12 months subjective good‐to‐excellent response in 77.8% of dogs in the ILIT/SCIT group was seen.

Conclusion and Clinical Relevance

The efficacy of this ILIT protocol was comparable with LVM monotherapy at six months. When ILIT was continued with SCIT, a favourable response was seen.
High Performance Vanadium Redox Flow Battery Electrodes
Authors: Gass Kaycee , Bera Bapi , Aaron Doug S. , Mench Matthew M.
Published: April 2023

A high temperature ammonia treatment was applied to carbon felt electrodes to enhance vanadium redox flow battery (VRFB) performance. Samples were heated to 900 °C in the presence of ammonia gas for up to 4 h. While all heating times resulted in an overall improvement in current density at 80% voltage efficiency, samples treated for 4 h showed the greatest increase in current density (325%) compared to untreated carbon felt. Raman spectroscopy showed a 74% increase in edge sites as a result of the 4 h treatment. Electrochemical surface area increased by 142% and scanning electron microscopy showed the appearance of pores on felt fiber surfaces, indicating that the performance improvement may be due to enhanced surface area in addition to functionalization. Impedance spectroscopy showed decreased charge transfer resistance and increased durability (during cycling) compared to other published electrode treatments. These results indicate that heated ammonia can be used to increase the performance of electrodes for vanadium flow battery applications, with excellent durability.
Physics simulation via quantum graph neural network
Authors: Collis Benjamin , Patel Saahil , Koch Daniel , Cutugno Massimiliano , Wessing Laura , Alsing Paul M.
Published: April 2023

We develop and implement two realizations of quantum graph neural networks (QGNN), applied to the task of particle interaction simulation. The first QGNN is a speculative quantum-classical hybrid learning model that relies on the ability to directly utilize superposition states as classical information to propagate information between particles. The second is an implementable quantum-classical hybrid learning model that propagates particle information directly through the parameters of RX rotation gates. A classical graph neural network (CGNN) is also trained in the same task. Both the Speculative QGNN and CGNN act as controls against the Implementable QGNN. Comparison between classical and quantum models is based on the loss value and accuracy of each model. Overall, each model had a high learning efficiency, in which the loss value rapidly approached zero during training; however, each model was moderately inaccurate. Comparing performances, our results show that the Implementable QGNN has a potential advantage over the CGNN. Additionally, we show that a slight alteration in hyperparameters in the CGNN notably improves accuracy, suggesting that further fine tuning could mitigate the issue of moderate inaccuracy in each model.
Lead-vocal level in recordings of popular music
1946–2020
Authors: Gerdes Karsten , Siedenburg Kai
Published: April 2023

Lead vocals constitute the central element of popular music. Here, the lead-vocal-to-accompaniment level ratio (LAR) was estimated from representative recordings of popular music. Measuring the LAR from 1946 to 2020, two distinct phases were observed: the average LAR decreased from around 5 dB to 1 dB until around 1975 but remained static from thereon. Comparing the LAR across musical genres, positive values were observed for Country, Rap, and Pop, values around zero for Rock, and negative values for Metal. Solo artists featured consistently higher LAR values compared to bands. These results establish a baseline for a central aspect of music mixing.
Parametric analysis of the impact of geometry on room modes at low frequencies using wave-based simulation
Authors: Algargoosh Alaa , Allam Ahmed
Published: April 2023

Room modes at low frequencies strongly influence the perception of sound in a room, which can enhance or deteriorate the acoustic experience. Previous research showed that low-frequency modes are also linked to the emotional impact of the acoustic environment; this link calls for further understanding of the effect of resonance at low frequencies on sound perception. However, most auralization software programs adopt geometric-based simulations, which are not accurate at low frequencies. In this work, we adopt wave-based simulations to characterize room modes at low frequencies depending on the room geometry through a parametric analysis. The study outlines the contribution of architectural elements, such as domes and sub-volumes, in shaping the acoustic environment by manipulating low frequencies.
Low-intensity triggered release with spatial and temporal control using antibubbles
Authors: Athanassiadis Athanasios , Moreno-Gomez Nicolas , Poortinga Albert T. , Fischer Peer
Published: April 2023

One approach to ultrasound therapy is to use therapeutic agents that can be activated by focused ultrasound when they reach a specific site in the body. Commonly, such agents are loaded on the surfaces of microbubbles, which respond strongly to ultrasound and shed the payload. However, microbubbles require high pressures and mechanical indices to burst (typically above 200 kPa, MI > 0.2). Moreover, the quantity and types of therapeutic payload that can be delivered by microbubbles are limited because payloads must be attached to the microbubble surface. Here, we show how these limitations can be overcome by using stabilized antibubbles as an ultrasound-responsive carrier. Antibubbles are liquid droplets encased within an air bubble. Because therapeutic payloads can be encapsulated in the core, larger volumes can be carried per antibubble. Additionally, by carrying payloads in the volume rather than on the surface, a wider variety of payloads can be carried. Through experiments we demonstrate that antibubbles respond strongly to ultrasound and can release payloads with pressures below 50 kPa (MI = 0.05) for certain formulations. By modifying the formulation, we show that the release pressure and temporal release profile can be tuned. Finally, we show that the bursting is highly selective in space, demonstrating that antibubbles can be used for precise delivery of payloads using shaped, low-intensity ultrasound fields.
Implementing neural networks in low-latency audio applications
Authors: Gomes Lobato Thiago Henrique , Sottek Roland , Vorlaender Michael
Published: April 2023

The use of neural networks is becoming increasingly prevalent due to their ability to represent complex relationships and solve complex problems. However, implementing these models in systems that require low-latency output can be challenging, especially for practitioners who are used to developing their models in controlled environments like Python notebooks. Another issue is the high computational cost of complex models, which limits the minimum possible latency. This paper presents approaches for deploying models in audio applications, discusses the advantages and disadvantages of each approach, and presents strategies to reduce the inference cost of models without significantly sacrificing accuracy, using techniques such as model quantization. To illustrate these methods, example implementations of real-time beamforming deconvolution and real-time music DSP processing are shown.
Microphones: A bit of history
Authors: Thompson Stephen C.
Published: April 2023

The earliest commercially successful microphone design was the carbon microphone, whose original patent was filed by Emile Berliner in 1877. An interesting variant of the basic carbon microphone was a dual diaphragm microphone patented by Granville Woods in 1883. The basic carbon microphone provided adequate performance at low cost and remained in service in the telephone system for at least the next century. Other microphone technologies can also be found in the early patent literature, though their commercial acceptance was delayed until electronic amplification was possible. The eventual development of vacuum tube amplifiers enabled the development of the condenser microphone, whose initial patent was filed in 1916. Condenser microphones provide the improvement of wide bandwidth and flat response compared to carbon microphones. The invention in the 1960s of high quality electret materials enabled the manufacture of low cost electret microphones that quickly displaced carbon mics in telephones and most commercial devices for at least the next 40 years. Then, in the early years of the 21st century, condenser microphones implemented in silicon, also known as MEMS microphones, took over in high all volume applications. This paper will discuss this history and the current state of the art.
Microphone vibration sensitivity: Frequency response, measurement error, and usage of measured responses in lumped element simulations
Authors: King Charles B.
Published: April 2023

Microphones are designed to respond to acoustic pressure fields, but they can also be excited by external sources of mechanical vibration. In hearing aids, feedback is a difficult problem to resolve due to the high gain used to amplify sounds. A new method to measure a microphone’s “intrinsic vibration sensitivity” was introduced at the 183rd ASA conference in Nashville. This paper will describe details of a practical measurement and how these details impact measurement error. It will demonstrate how the measured response canbe integrated into lumped circuit models for analysis in SPICE or FEA programs. Utilizing measurement error and lumped circuit models, a description of how error of the complete system varies over frequency will be shown.
An investigation of rooms with reflection-free zones using finite-difference methods in curvilinear coordinates
Authors: Bellows Samuel D. , Leishman Timothy W.
Published: April 2023

Small-room acoustical designers have applied the concept of early reflection-free zones (RFZs) to recording studio control rooms and other critical listening environments. The rooms' unique shapes and treatments create listening regions with minimal early reflections to improve audio monitoring. One standard tool for studying room acoustics is the finite-difference(FD) method. However, it typically uses regular Cartesian grids, which lead to stair-casing discretization effects for arbitrarily shaped boundaries, including those of the RFZ room. This work presents how FD methods in curvilinear coordinates overcome these difficulties. Both modal and time-domain analyses yield insights into the acoustical differences between RFZ and rectangular shoebox rooms.
Effect of musical instrumentation on perception of reverberation in simulated listening environments
Authors: Jasinski Christopher M. , Celmer Robert
Published: April 2023

The reverberance of a performance venue is often characterized by an important metric, reverberation time. In order for architects, acousticians, and performers to better understand the value of knowing and predicting the reverberation time in different spaces, the just-noticeable-difference (JND) is often cited. The established JND for reverberation time is approximately 5% of the reference reverberation, noted in the standard ISO 3382-1. This value was determined using impulsive sound, meaning it may not provide a complete picture for applications related to music. This study aimed to evaluate several elements of musical performance that may alter the perception of reverberation in a simulated listening environment. Primarily, the effect of instrumentation was investigated, including the use of solo, small ensemble, full orchestra, and vocal recordings for comparison. Results were generated using test participants listening to multiple soundfields and providing subjective evaluation. Reverberant soundfields were created in an anechoic listening environment and auralizations were produced using ODEON room acoustics software. Results indicated statistically significant mean differences in reverberation perception between musical instrumentation groups used during experiments. [Work supported by The Paul S. Veneklasen Research Foundation.]
Hydraulic flow noise characterization of spool valves using experimental techniques
Authors: Paprocki Carter A. , Malladi Sriram , Barnard Andrew
Published: April 2023

This research was conducted to characterize and develop a deeper understanding of the hydraulic flow noise for a spool valve. Hydraulic noise was analyzed to study the interaction of the valve spool and the flow noise generation to isolate where in the spool articulation the most noise was generated. The goal was to correlate turbulent fluid flow in pressurized hydraulic circuits to different spool positions while isolating what factors were the main drivers of spool noise generation. The experiments were conducted on a valve controlled by a closed-circuit hydraulic system, using this system fluid-born noise could be isolated from other noisy mechanisms and a noise profile of each could be measured. It was found that internal spool geometry and flow channel open area played the largest role in valve noise generation for the valve. In the future, more valves could be tested to develop a robust profile library using the test methods developed.
Recollections of David M. Green
Authors: Hafter Ervin R. , McFadden Dennis
Published: April 2023

In addition to being wickedly smart, David Green had many characteristics that contributed to his great success as a scientist, scholar, mentor, and friend. ERH and family interacted with the Greens over many decades, during sabbatical years, and in travel to exotic places. DM worked with Dave on two major projects—the acoustical reenactment of the JFK assassination, and an NRC committee studying the effects of intense sounds on marine mammals. Recollections will be shared, some true. Dave's work was marked by an unflagging determination to fully understand the problem at hand, and he was amazingly quick at comprehending new information and organizing it into his extraordinary memory. While current and future generations of scientists will remember him for the paradigm shift that his work produced in experimental psychology and neuroscience, those of us who knew him personally will remember an honest, generous, kind, and unpretentious fellow who was just as knowledgeable about sports, art, and current events as about science. We also will not forget that he was a truly fun guy who enjoyed nothing better than a good joke about the world's foibles or about his own notorious frugality.
Dave Green as a mentor
Authors: Strickland Elizabeth A.
Published: April 2023

In addition to his influence on the field through his science, Dave Green also had a direct impact through his role as a mentor for many students, post docs, and visitors to his labs. In this talk, I will discuss Dave’s history as a mentor, and reflect on experiences as the last post doc to come to the lab.
Generative optimization of sound insulation of composites using deep learning networks
Authors: Sang Sheng , Xu Chen
Published: April 2023

Composites have been widely used in the field of acoustics due to their extraordinary ability of sound insulation. To date, the design of acoustic composites relies primarily on the expertise of engineers and experimental tests. This preliminary study outlines a deep learning (DL) based approach to optimize the microstructure of the composite bars to achieve the best performance in sound insulation. This approach first trains DL networks using data generated using finite element simulation to predict the pressure amplitude and energy of the output waves, then a genetic algorithm (GA) uses the DL model as its evaluation function and generates new designs. The results indicate that a combination of DL and GA can generate Pareto-optimal designs to satisfy the specific needs of engineering projects. We demonstrate that starting with a quite small data set (less than of all possible designs) and applying a DL approach is an efficient and robust method to obtain optimal designs. The DL model is accurate in its predictions which enables the GA to find unique composite designs that are optimal for sound insulation.
Hybrid analog-sampled adaptive active noise control
Authors: Vered Yoav , Elliott Stephen J.
Published: April 2023

Feedforward adaptive controllers are widely used for active noise control. For good broadband performance, the secondary path delay must be shorter than that of the primary path. In this work, a hybrid analog-sampled adaptive feedforward controller is developed to eliminate the additional delay associated with the sampling. An adaptive finite-impulse-response system is used for the sampled controller, and a state filtered adaptive linear combiner is used for the analog controller. Two approximations are used for the linear combiner. The first minimizes the added electrical noise by having individual state filters, all driven by the reference signal, while the second gives a superior bandwidth by driving each component filter with the output of the previous one. A sampled version of the normalized projection algorithm is developed for the analog controller. The different error paths used to filter the reference signal for the controllers’ adaptation are emphasized. Finally, the performance of the proposed controller is assessed. The results highlight the capabilities of the suggested controller and the different state filters, especially their ability to achieve significant attenuation levels close to the causality limit and when long delays of the reference signal are required.
Auditory-inspired adaptive frequency tracking
Authors: Peddinti Vijay
Published: April 2023

One of the best frequency trackers to date is the human (mammalian) auditory system, which has evolved through millions of years of resolving classification problems. It is a versatile, elegant and powerful sound processing unit. It excels in detecting, estimating, and classifying multiple targets simultaneously even in noisy environments. Hence, mimicking even some features of the auditory system could be beneficial in developing superior frequency tracking and classification algorithms. An auditory inspired adaptive synchrony capture filterbank (SCFB) signal processing architecture for tracking signal frequency components was proposed in a related paper [JASA (2013)]. The SCFB architecture consists of a fixed array of traditional, passive linear, gammatone filters in cascade with a bank of three adaptively tunable bandpass filters that form a frequency-discriminator-loop (FDL). The SCFB exhibits many desirable properties for processing speech, music, and other complex sounds. In recent work (Dec 2021), the algorithm was modified using adaptive tuning parameters, and a generalized way to determine/suppress voiced and unvoiced (silent) regions. This modified algorithm estimates frequencies with higher accuracy even in the presence of closely spaced input tones. Preliminary analysis with synthetic, human speech and humpback/whale-call signals demonstrates that the revised algorithm performs well. This talk will focus on the latest updates.
Understanding the impact of acoustics on the learning ability among children with autism in the classroom
Authors: Tufvesson Catrin
Published: April 2023

A pronounced ambition concerning the educational policy in Sweden is to organize an all-inclusive school, meaning that schools should be able to meet the needs of all children, irrespective of their capacities and conditions. However, there were no specific guidelines for the school environment as a learning environment. In my thesis The Human Environment Interaction-model is implemented to identify environmental factors that affect children with ADHD, autism, and Down's syndrome and their ability to concentrate in their learning environment at school. The issue was not to dismiss any of the additional resources these children are in need of; instead it was to suggest how to arrange learning environments in the most supportive way possible. This presentation will focus on aspects of acoustics which are—and which are not—beneficial for children with autism. The results from the thesis have been an underlying basis for further work at the National Agency for Special Needs Educations and Schools in Sweden, which will also be presented. The developed work at the Agency resulted in a tool with guidelines to make the learning environment more accessible for all children in existing classrooms, but it can also be implemented in the building process.
Soundfield amplification for primary school students on the autism spectrum: Research findings and classroom applications
Authors: Wilson Wayne J. , Harper-Hill Keely , Downing Cerys , Armstrong Rebecca , Perrykkad Kelsey , Rafter Mary , Ashburner Jill
Published: April 2023

Sound field amplification (SFA) has recently attracted interest as an inclusive classroom adjustment for children on the autism spectrum. When functioning optimally, SFA improves the signal-to-noise ratio in the classroom by maintaining the teacher’s voice at a higher level than the classroom noise. In this paper, we will report on the results of a randomised controlled trial of SFA over two semesters for 13 children (9 males, aged 7.6 to 8.4 years) on the spectrum and 17 children (7 males, aged 7.6 to 9.3 years) not on the spectrum in their third year of schooling in 10 elementary schools in Australia. SFA was found to assist children on the spectrum to improve their skills in an area of phonological processing known to be important to reading acquisition, but not their skills in attention, memory or educational achievement. In conclusion, SFA continues to show sufficient potential for supporting children on the spectrum in the classroom to warrant its trialing on a case-by-case basis. Realistic expectations as to the short-term benefits of SFA are needed.
Noise-induced vocal flexibility in Hipposiderid and Rhinolophid bats
Authors: Luo Jinhong , Wei Tingting , Ma Nina , Lin Aiqing
Published: April 2023

Although James Simmons’s pioneering work on bats’ target ranging capability by echolocation has been widely acknowledged, his contributions to other fields of bat echolocation have often been underappreciated. For example, James Simmons was probably the first to observe that echolocating bats can employ remarkable vocal flexibilities to counter masking noise effects on target ranging [Simmons et al., https://doi.org/10.1121/1.1914154 (1974)], a research topic that has only gained popularity in the bioacoustics community in recent two decades or so. In this talk, we present the latest data on noise-induced vocal flexibility of five species of bats, including Hipposideros pratti and four Rhinolophids. All bats emit echolocation calls consisting of a constant frequency component and a frequency modulated component. We first show that both Rhinolophid and hipposiderid bats possess a highly developed vocal flexibility to counter noise interference. Then, with H. pratti we demonstrate that the expression of vocal flexibility by the same individual was affected by several factors, such as the behavioral context or task, and history of training, which were believed to mediate the noise-induced vocal flexibility of humans only. These results emphasize the value of the comparative approach in understanding the vocal production control of mammals.
Effects of absolute range and echo phase on range discrimination in bottlenose dolphins (Tursiops truncatus)
Authors: Christman Katie A. , Finneran James J. , Gentner Tim , Houser Dorian , Mulsow Jason
Published: April 2023

Echo-delay (range) resolution is a critical feature of animal biosonar. In 1973, Jim Simmons was the first scientist to test bat range discrimination thresholds at a variety of absolute ranges. He used a two alternative-force-choice paradigm with two phantom echo generators (PEGs) and compared the results to the bats’ performance with physical targets. In the present study, methods similar to Simmons’ 1973 study were used to test two dolphins’ range discrimination thresholds using a two channel PEG system. Range discrimination thresholds were tested at seven different absolute ranges between 1.75 and 20 m. Ranges were simulated by manipulating echo-delay while relative echo level was held constant for all parameters. To examine potential effects of echo phase, measurements were repeated at a 7 m range while randomizing echo phase. For both subjects, range discrimination thresholds increased exponentially with absolute range. Randomizing echo phase did not significantly change thresholds, suggesting that dolphins use the envelope of the echo waveform to determine range versus the fine structure.
Passive acoustic exploration of the ocean
Authors: Barclay David R.
Published: April 2023

Encoded in the spectral density, spatial variability, and directionality (spatial coherence) of the ambient sound field is information on the generation mechanisms of sound and the properties of the ocean propagation environment and its boundaries. Through field and observatory measurements, and analytical and computational models of the underwater sound field, a research program has been pursued that asks, “What can we learn about the ocean by listening?” Large acoustic data sets have been exploited to develop an estimate of the effective source level per unit area of surface generated noise. In complement, a methodology for precisely partitioning the sound field into ship generated and wind generated components by exploiting the vertical noise directionality has been demonstrated. Models of the spatial properties of wind driven and ship generated sound have further been used to estimate the geoacoustic properties of the seabed, the depth of mix layer, depth-averaged pH, and localize a source in bearing and azimuth using only a pair of vertically oriented omnidirectional hydrophones. An autonomous passive acoustic profiler, The Deep Acoustic Lander (DAL), recently made measurements of the ambient sound field from the surface to the bottom of the Challenger Deep, Mariana Trench, precisely determining the mixing of a locally- and distantly generated contributions to the sound field. Meanwhile, DAL measurements at the Endeavour hydrothermal vent field have revealed components of the sound field generated by vent activity.
Ambient sound levels, directionality, and transport velocity around a seamount measured by a deep-drifting acoustic vector sensor
Authors: Thode Aaron M. , Bevans Dieter , Laferriere Alison B. , Berkenpas Eric , Shepard Mike , Freeman Lauren A.
Published: April 2023

In September 2022 an opto-acoustic drifter was deployed several times in the vicinity of the Kelvin seamount (38°49’N, 64°2’W) in the North Atlantic Ocean, which rises to a depth of 1500 m from a 5 km deep abyssal plain. The “SQUALL-E” drifter incorporates stereo video cameras, vertical (1.75 m aperture) and tetrahedral hydrophone arrays, and a 2-D Geospectrum M35 acoustic vector sensor. One overnight deployment descended to 250 m depth, and a another to 400 m depth, which resulted in highly different drift rates. The M35 sensor demonstrated the ability to estimate the directionality of ambient sounds between 1 and nearly 30 kHz. Sperm whales, delphinids, various vessels, and other discrete and distributed sources were detected. For both deployments we present distributions of ambient sound levels, azimuthal and elevation angles, and transport velocity. We discuss how these distributions evolved throughout the deployments. [Work sponsored by ONR TFO program.]
Video tributes to Jeffrey A. Nystuen
Authors: Yang Jie , Miksis-Olds Jennifer , Gemba Kay L.
Published: April 2023

This video presentation is dedicated to the career and legacy of Jeffrey A. Nystuen.
Instrumentation for histotripsy ultrasound therapy: Evolution toward the clinic
Authors: Hall Timothy L. , Sukovich Jonathan R. , Cannata Jon , Fowlkes J. Brian , Xu Zhen
Published: April 2023

Histotripsy is a method of ultrasound therapy using very intense, focused sound fields to fragment tissue causing controlled and localized necrosis principally through mechanical actions of cavitation. Highly specialized instrumentation (transducers and electrical drivers) is required to produce these extreme sound fields for research into cavitation physics and therapeutic applications of histotripsy. This paper will describe the evolution of histotripsy instrumentation from the first devices up to the latest phased-array systems with hundreds of channels and transmit-receive capability. While early histotripsy systems used tone bursts generators with limited bandwidth (called “class-D” circuits) for transducer excitation, more recent ones are based on a switched inductor principle to produce shorter duration acoustic emissions. This method has been tested for peak excitation voltages up to 5 kV and 40 A in compact modular systems suitable for phased-arrays. Receive of acoustic signals by the therapeutic array for aberration correction and cavitation mapping is achieved by sensing current generated by the transducer greatly simplifying transmit-receive circuitry while maintaining very large dynamic range. A novel distributed architecture was developed for data handling and signal processing using off-the-shelf FPGA evaluation modules interfaced by ethernet. These latest features will be key to successful clinical translation and widespread adoption of histotripsy.
Technology development for acoustic hemostasis
Authors: Crum Lawrence A.
Published: April 2023

In trauma cases, the often immediate (and necessary) requirement is to stop uncontrolled bleeding; indeed, in combat, more than 50% of deaths result from exsanguination. With the development of ultrasound image-guided High Intensity Focused Ultrasound (HIFU) devices, “Acoustic Hemostasis” is not only possible but has the ability to terminate uncontrolled bleeding as well as for many applications of considerable benefit to medicine. In this lecture, various technology development devices and methodologies will be described that have the potential for commercial development for a wide variety of medical indications.
A compact high performance micro-electro-mechanical systems microphone
Authors: Ma Yunfei , Shubham Shubham , Kuntzman Michael , Cheng Jen-I , Ouyang Jing
Published: April 2023

This paper reports on the development of a MEMS capacitive microphone design with 72 dBA signal-to-noise-ratio (SNR) in a compact 3.4 × 2.3 × 0.7 mm3package. The design incorporates a circular diaphragm disc suspended on one end of the cantilever beam. The diaphragm, under the bias conditions, is supported using peripheral and center protrusions extended from the back plate. The design optimization is targeted to achieve high sensitivity and low damping noise to achieve maximum SNR possible in the mentioned footprint. Finite element modeling (FEM) combined with the lumped element circuit modeling have been implemented to realize the microphone performance. The results have been validated against the measurement with very good correlation of sensitivity, noise and total harmonic distortion (THD). With the sensitivity of −35 dBV (ref. 1 V/Pa at 1 kHz) and acoustic overload point of 134 dBSPL, this is one of the highest performing MEMS analog microphone reported today. Therefore, it is very well suited for audio applications such as mobile phones, true wireless stereo (TWS) earphones, hearing aids and automotive, which demand miniaturized size, low cost and high performance.
Program assessment in undergraduate acoustics at Kettering University
Authors: Ludwigsen Daniel , Kumon Ronald E.
Published: April 2023

Kettering University has been teaching acoustics as part of undergraduate engineering for decades, and the senior-level acoustics laboratory course has assumed a critical role in the continuous improvement process for our ABET-accredited programs in Applied Physics and Engineering Physics. This project-based course addresses learning objectives focused on transferable skills in test and measurement, literature and theoretical foundations, and computational modeling. These are set in the context of two modules, on sound source directivity and modal testing. The assessment structure is built around rubrics, used for both formative and summative evaluation of student performance on authentic tasks including recording activity in lab notebooks and scientific writing. A 32-question multiple choice instrument is deployed as a pre-test and post-test to assess gains in content knowledge from the course. Finally, we discuss specific examples of assessment for effective teamwork (ABET EAC Outcome 5) and developing and conducting experiments and analyzing and interpreting data (ABET EAC Outcome 6).
Strategies for assessment of student learning outcomes via the final project in a general education acoustics course
Authors: Balant Anne C. , Lai Heather L.
Published: April 2023

Learning outcomes of the final project in an undergraduate general education acoustics course were assessed via three short essay questions on an open book final exam. For the project, students construct a simple sound-making device or musical instrument that produces at least four different sounds using ordinary household objects, recyclables, etc. They are required to develop a hypothesis about how changes in the device will change the properties of the sounds. They then test their hypotheses using spectrograms, FFT measurements, and/or sound level measurements. The written responses of 60 students were downloaded and stripped of identifiers. The first two essay questions were designed to assess whether students could connect the steps of their project with the scientific method and explain therationale for their choice of measurement methods based on their hypothesis. These results were assessed via rubrics. The third question was an open-ended reflection on what they learned about acoustics by completing the project, and how they learned it. These responses were assessed via qualitative data analysis. Results, key findings, and implications for the design of the assignment and future assessments will be discussed.