Aspects of room acoustics, vision and motion in the human auditory perception of space

The human sense of hearing contributes to the awareness of where sound-generating objects are located in space and of the environment in which the hearing individual is located. This auditory perception of space interacts in complex ways with our other senses, can be both disrupted and enhanced by sound reflections, and includes safety mechanisms which have evolved to protect our lives, but can also mislead us. This dissertation explores some selected topics from this wide subject area, mostly by testing the abilities and subjective judgments of human listeners in virtual environments. Reverberation is the gradually decaying persistence of sounds in an enclosed space which results from repeated sound reflections at surfaces. The first experiment (Chapter 2) compared how strongly people perceived reverberation in different visual situations: when they could see the room and the source which generated the sound; when they could see some room and some sound source, but the image did not match what they heard; and when they could not see anything at all. There were no indications that the visual image had any influence on this aspect of room-acoustical perception. The potential benefits of motion for judging the distance of sound sources were the focus of the second study (Chapter 3), which consists of two parts. In the first part, loudspeakers were placed at different depths in front of sitting listeners who, on command, had to either remain still or move their upper bodies sideways. This experiment demonstrated that humans can exploit motion parallax (the effect that closer objects appear faster to a moving observer than farther objects) with their ears and not just with their eyes. The second part combined a virtualisation of such sound sources with a motion platform to show that the listeners’ interpretation of this auditory motion parallax was better when they performed this lateral movement by themselves, rather than when they were moved by the apparatus or were not actually in motion at all. Two more experiments were concerned with the perception of sounds which are perceived as becoming louder over time. These have been called “looming”, as the source of such a sound might be on a collision course. One of the studies (Chapter 4) showed that western diamondback rattlesnakes (Crotalus atrox) increase the vibration speed of their rattle in response to the approach of a threatening object. It also demonstrated that human listeners perceive (virtual) snakes which engage in this behaviour as especially close, causing them to keep a greater margin of safety than they would otherwise. The other study (section 5.6) was concerned with the well-known looming bias of the sound localisation system, a phenomenon which leads to a sometimes exaggerated, sometimes more accurate perception of approaching compared to receding sounds. It attempted to find out whether this bias is affected by whether listeners hear such sounds in a virtual enclosed space or in an environment with no sound reflections. While the results were inconclusive, this experiment is noteworthy as a proof of concept: It was the first study to make use of a new real-time room-acoustical simulation system, liveRAZR, which was developed as part of this dissertation (Chapter 5). Finally, while humans have been more often studied for their unique abilities to communicate with each other and bats for their extraordinary capacity to locate objects by sound, this dissertation turns this setting of priorities on its head with the last paper (Chapter 6): Based on recordings of six pale spear-nosed bats (Phyllostomus discolor), it is a survey of the identifiably distinct vocalisations observed in their social interactions, along with a description of the different situations in which they typically occur.Das menschliche Gehör trägt zum Bewusstsein dafür bei, wo sich schallerzeugende Objekte im Raum befinden und wie die Umgebung beschaffen ist, in der sich eine Person aufhält. Diese auditorische Raumwahrnehmung interagiert auf komplexe Art und Weise mit unseren anderen Sinnen, kann von Schallreflektionen sowohl profitieren als auch durch sie behindert werden, und besitzt Mechanismen welche evolutionär entstanden sind, um unser Leben zu schützen, uns aber auch irreführen können. Diese Dissertation befasst sich mit einigen ausgewählten Themen aus diesem weiten Feld und stützt sich dabei meist auf die Testung von Wahrnehmungsfähigkeiten und subjektiver Einschätzungen menschlicher Hörer/-innen in virtueller Realität. Beim ersten Experiment (Kapitel 2) handelte es sich um einen Vergleich zwischen der Wahrnehmung von Nachhall, dem durch wiederholte Reflexionen an Oberflächen hervorgerufenen, sukzessiv abschwellenden Verbleib von Schall in einem umschlossenen Raum, unter verschiedenen visuellen Umständen: wenn die Versuchsperson den Raum und die Schallquelle sehen konnte; wenn sie irgendeinen Raum und irgendeine Schallquelle sehen konnte, dieses Bild aber vom Schalleindruck abwich; und wenn sie gar kein Bild sehen konnte. Dieser Versuch konnte keinen Einfluss eines Seheindrucks auf diesen Aspekt der raumakustischen Wahrnehmung zu Tage fördern. Mögliche Vorteile von Bewegung für die Einschätzung der Entfernung von Schallquellen waren der Schwerpunkt der zweiten Studie (Kapitel 3). Diese bestand aus zwei Teilen, wovon der erste zeigte, dass Hörer/-innen, die ihren Oberkörper relativ zu zwei in unterschiedlichen Abständen vor ihnen aufgestellten Lautsprechern auf Kommando entweder stillhalten oder seitlich bewegen mussten, im letzteren Falle von der Bewegungsparallaxe (dem Effekt, dass sich der nähere Lautsprecher relativ zum sich bewegenden Körper schneller bewegte als der weiter entfernte) profitieren konnten. Der zweite Teil kombinierte eine Simulation solcher Schallquellen mit einer Bewegungsplattform, wodurch gezeigt werden konnte, dass die bewusste Eigenbewegung für die Versuchspersonen hilfreicher war, als durch die Plattform bewegt zu werden oder gar nicht wirklich in Bewegung zu sein. Zwei weitere Versuche gingen auf die Wahrnehmung von Schallen ein, deren Ursprungsort sich nach und nach näher an den/die Hörer/-in heranbewegte. Derartige Schalle werden auch als „looming“ („anbahnend“) bezeichnet, da eine solche Annäherung bei bedrohlichen Signalen nichts Gutes ahnen lässt. Einer dieser Versuche (Kapitel 4) zeigte zunächst, dass Texas-Klapperschlangen (Crotalus atrox) die Vibrationsgeschwindigkeit der Schwanzrassel steigern, wenn sich ein bedrohliches Objekt ihnen nähert. Menschliche Hörer/-innen nahmen (virtuelle) Schlangen, die dieses Verhalten aufweisen, als besonders nahe wahr und hielten einen größeren Sicherheitsabstand ein, als sie es sonst tun würden. Der andere Versuch (Abschnitt 5.6) versuchte festzustellen, ob die wohlbekannte Neigung unserer Schallwahrnehmung, näherkommende Schalle manchmal übertrieben und manchmal genauer einzuschätzen als sich entfernende, durch Schallreflektionen beeinflusst werden kann. Diese Ergebnisse waren unschlüssig, jedoch bestand die Besonderheit dieses Versuchs darin, dass er erstmals ein neues Echtzeitsystem zur Raumakustiksimulation (liveRAZR) nutzte, welches als Teil dieser Dissertation entwickelt wurde (Kapitel 5). Abschließend (Kapitel 6) wird die Schwerpunktsetzung auf den Kopf gestellt, nach der Menschen öfter auf ihre einmaligen Fähigkeiten zur Kommunikation miteinander untersucht werden und Fledermäuse öfter auf ihre außergewöhnliches Geschick, Objekte durch Schall zu orten: Anhand von Aufnahmen von sechs Kleinen Lanzennasen (Phyllostomus discolor) fasst das Kapitel die klar voneinander unterscheidbaren Laute zusammen, die diese Tiere im sozialen Umgang miteinander produzieren, und beschreibt, in welchen Situationen diese Lauttypen typischerweise auftreten

Patent Law: Controversy in the Federal Circuit over Product-by-Process Claims

Atlantic Thermoplastics Co. v. Faytex Corp., 970 F.2d 834 (Fed. Cir.), reh\u27g en banc denied, 974 F.2d 1279 (1992)

A Conceptual Harmonization between the SSA Disability Determination Process and ICF and DOT Frameworks: A Guide to Assessing the Mental Residual Functional Capacity of Individuals with Autism Spectrum Disorders

The aim of the current project is to create a useful product that cross-walks the Social Security Administration’s (SSA) Mental Residual Functional Capacity Assessment (MRFCA) with the International Classification of Functioning (ICF) and the Dictionary of Occupational Titles (DOT) applied to a population of individuals with Autism Spectrum Disorders (ASD). SSA’s MRFCA is cross-walked with the ICF in order to allow for a more in depth and functional breakdown of the purposefully more generic categories of the MRFCA. Worker Functions derived from the DOT are then added to the SSA/ICF crosswalk in order to better operationalize the functional manifestations associated with disability states as they occur in a natural (work) environment. Finally, a decision tree is developed from the crosswalk to increase ease of use of the product, titled the MRFCA Decision Tree. ASD was chosen as an exemplar to test this process. Inter-rater reliability on the MRFCA Decision Tree is assessed. The outcomes are the following: (a) A MRFCA Decision Tree that will allow a disability examiner to derive a more reliable disability decision when assessing individuals with ASD,(b) A breakdown of the current DDP process including problem areas and improvement suggestions based on the implementation of the decision tree, and (c) A narrative review of how coordinating the DOT with the ICF can provide a deeper understanding of how functional manifestations of a disability relate to job demands. Plans for future research aimed at improving the decision tree are discussed

Providing Education to Enhance Wildlife Conservation in South Africa Through the First Wildlife School for Game Rancers - A Grassroots Effort by Government Authorized Conservationists

The establishment of the game ranching industry in South Africa has resulted in the conversion of 20 million hectares of marginal agricultural land to an economically viable and conservation oriented industry. The single biggest driving factor in the growth of the game ranching industry in South Africa was the promulgation of the Game Theft Act 105 of 1991 which conferred private ownership of game. Due to the Act, wildlife became economically viable and were managed according to the creation of this new market. The growth in game animals has reached its highest point since 1850 with over 20 million animals. In 1992, South Africa signed the International Convention on Biodiversity whereby the country committed itself to a goal of 12% of the country would be preserved for wildlife biodiversity by 2021. By 2016, the Department of Environmental Affairs (DEA) had determined that South Africa’s terrestrial protected area fell far short of the 12% agreed upon by the country. The DEA had determined that South Africa would have to depend on the assistance and conservation of the game ranching industry in order to meet the 12% target. In 2017it was realized that a wildlife school for game farmers was needed, to address utilizing natural resources in a manner that supports sustainability and improves economic prospects while upholding conservation ethics. To help unify the industry and address the unknowns, the first Wildskool was developed to provide direct face to face education

Evaluation of a Telerehabilitation System for Community-Based Rehabilitation

The use of web-based portals, while increasing in popularity in the fields of medicine and research, are rarely reported on in community-based rehabilitation programs.  A program within the Pennsylvania Office of Vocational Rehabilitation’s Hiram G. Andrews Center, the Cognitive Skills Enhancement Program (CSEP), sought to enhance organization of program and participant information and communication between part- and full-time employees, supervisors and consultants. A telerehab system was developed consisting of (1) a web-based portal to support a variety of clinical activities and (2) the Versatile Integrated System for Telerehabilitation (VISyTER) video-conferencing system to support the collaboration and delivery of rehabilitation services remotely.  This descriptive evaluation examines the usability of the telerehab system incorporating both the portal and VISyTER. Telerehab system users include CSEP staff members from three geographical locations and employed by two institutions. The IBM After-Scenario Questionnaire (ASQ) and Post-Study System Usability Questionnaire (PSSUQ), the Telehealth Usability Questionnaire (TUQ), and two demographic surveys were administered to gather both objective and subjective information. Results showed generally high levels of usability.  Users commented that the telerehabilitation system improved communication, increased access to information, improved speed of completing tasks, and had an appealing interface. Areas where users would like to see improvements, including ease of accessing/editing documents and searching for information, are discussed.        

The vocal development of the pale spear-nosed bat is dependent on auditory feedback

Funding: The research was funded by the Human Frontiers Science Program (grant no. RGP0058/2016), awarded to L.W. and S.C.V. S.C.V. was supported by a Max Planck Research Group (MPRG) and a UKRI Future Leaders Fellowship (MR/T021985/1). M.S. was funded by a grant from Deutsche Forschungsgemeinschaft (no. wi1518/17).Human vocal development and speech learning require acoustic feedback, and humans who are born deaf do not acquire a normal adult speech capacity. Most other mammals display a largely innate vocal repertoire. Like humans, bats are thought to be one of the few taxa capable of vocal learning as they can acquire new vocalizations by modifying vocalizations according to auditory experiences. We investigated the effect of acoustic deafening on the vocal development of the pale spear-nosed bat. Three juvenile pale spear-nosed bats were deafened, and their vocal development was studied in comparison with an age-matched, hearing control group. The results show that during development the deafened bats increased their vocal activity, and their vocalizations were substantially altered, being much shorter, higher in pitch, and more aperiodic than the vocalizations of the control animals. The pale spear-nosed bat relies on auditory feedback for vocal development and, in the absence of auditory input, species-atypical vocalizations are acquired. This work serves as a basis for further research using the pale spear-nosed bat as a mammalian model for vocal learning, and contributes to comparative studies on hearing impairment across species.Publisher PDFPeer reviewe

Motivations for relationships as sources of meaning : Ghanaian and South African experiences

Afrocentric paradigms reflect assumptions of the overarching importance of interconnectedness and social bonds in meaningful experiences. It is, however, not known if types of relatedness vary in importance as meaning sources in the subjective experiences of laypeople, or what the reasons are that they ascribe to the importance of relationships. The empirical and theoretical substantiation of philosophical assumptions is needed to provide a scientific basis for appropriate well-being interventions in African contexts. Therefore, this study aimed to empirically explore the relative importance of various types of relationships as sources of meaning and in particular why relationships are important to laypeople in relatively collectivist African contexts. Using a bottomup qualitative approach with quantification of responses, this study explored how prominently relationships featured as meaning sources compared to other domains of life and then, in particular, the motivations for the importance of various types of relationships as found in four African samples: a Ghanaian urban group (n = 389), a South African multicultural, English-speaking urban group (n = 585), and two South African Setswana-speaking groups (n = 512 rural, n = 380 urban). Findings showed that the relational domains of life, namely, family, interpersonal relations, spirituality/religion, and community/society, made up a large proportion of responses on what provides meaning in life in particular family and spirituality/religion with community/society occurring the least. The reasons for meaning experienced in various relationship types included domain-typical relational descriptors, such as contributions made or rewards received. However, many intrapersonal motives also emerged: inner well-being, happiness, joy, a sense of competence, and own growth. Material needs and harmony also surfaced as motivations for relational importance. Findings are aligned with African philosophical perspectives as far as the importance of relationships and the value attached to spirituality/religion are concerned, but contributed additionally by showing that different types of relationships vary in importance: close relationships are more important than community/societal relationships. Unearthing the reasons for the importance of relationships points toward a dialectic pattern of African individualism– collectivism in which independent and interdependent orientations flow together. Such knowledge is vital for the promotion of mental health and well-being in these contexts.This work from the FORT 3 and PURE-SA projects are based on the research supported in part by the National Research Foundation (NRF) of South Africa (Grant Numbers: 91557, 106050, 2069139, FA2006040700010, FA2007042600011, and 121948). Funding for PURE-SA were also obtained from the SANPAD (South Africa Netherlands Research Programme on Alternatives in Development 08/15), the South African Medical Research Council, the North-West University, South Africa, and the Population Health Research Institute, ON, Canada.http://www.frontiersin.org/Psychologyam2020Psycholog

The Role of Polycyclic Aromatic Hydrocarbons in Ultraviolet Extinction. I. Probing small molecular PAHs

We have obtained new STIS/HST spectra to search for structure in the ultraviolet interstellar extinction curve, with particular emphasis on a search for absorption features produced by polycyclic aromatic hydrocarbons (PAHs). The presence of these molecules in the interstellar medium has been postulated to explain the infrared emission features seen in the 3-13 $\mu$m spectra of numerous sources. UV spectra are uniquely capable of identifying specific PAH molecules. We obtained high S/N UV spectra of stars which are significantly more reddened than those observed in previous studies. These data put limits on the role of small (30-50 carbon atoms) PAHs in UV extinction and call for further observations to probe the role of larger PAHs. PAHs are of importance because of their ubiquity and high abundance inferred from the infrared data and also because they may link the molecular and dust phases of the interstellar medium. A presence or absence of ultraviolet absorption bands due to PAHs could be a definitive test of this hypothesis. We should be able to detect a 20 \AA wide feature down to a 3$\sigma$ limit of $\sim$0.02 A$_V$. No such absorption features are seen other than the well-known 2175 \AA bump.Comment: 16 pages, 3 figure, ApJ in pres

Missense mutations that cause Van der Woude syndrome and popliteal pterygium syndrome affect the DNA-binding and transcriptional activation functions of IRF6

Cleft lip and cleft palate (CLP) are common disorders that occur either as part of a syndrome, where structures other than the lip and palate are affected, or in the absence of other anomalies. Van der Woude syndrome (VWS) and popliteal pterygium syndrome (PPS) are autosomal dominant disorders characterized by combinations of cleft lip, CLP, lip pits, skin-folds, syndactyly and oral adhesions which arise as the result of mutations in interferon regulatory factor 6 (IRF6). IRF6 belongs to a family of transcription factors that share a highly conserved N-terminal, DNA-binding domain and a less well-conserved protein-binding domain. To date, mutation analyses have suggested a broad genotype–phenotype correlation in which missense and nonsense mutations occurring throughout IRF6 may cause VWS; in contrast, PPS-causing mutations are highly associated with the DNA-binding domain, and appear to preferentially affect residues that are predicted to interact directly with the DNA. Nevertheless, this genotype–phenotype correlation is based on the analysis of structural models rather than on the investigation of the DNA-binding properties of IRF6. Moreover, the effects of mutations in the protein interaction domain have not been analysed. In the current investigation, we have determined the sequence to which IRF6 binds and used this sequence to analyse the effect of VWS- and PPS-associated mutations in the DNA-binding domain of IRF6. In addition, we have demonstrated that IRF6 functions as a co-operative transcriptional activator and that mutations in the protein interaction domain of IRF6 disrupt this activity