Historically, the education of surgical navigation in minimally invasive neurosurgery has been constrained by several factors. Medical students have been required to physically be in the operating room to observe a teacher perform the different procedures. This restricts their opportunities to gain valuable hands-on experience in their field. An extended reality simulation system that employs auditory feedback in the form of sonification could be used to provide an inexpensive alternative to this traditional approach. Such a system would allow medical students to get practical experience with valuable insights during their initial years of training without requiring access to the operating room. In order to perform a first evaluation of the impact of sonification on neurosurgical learning using extended reality simulations, a prototype of a surgical simulation tool with six possible sonifications was implemented for the task of aligning a catheter against a target angle. The sonification types studied were spatial, psychoacoustic and direct parameter-mapping, each of which encoded the component angles either in parallel or sequentially. The sonifications were evaluated against each other and the baseline condition in a comparative mixed-design user study measuring the participants efficacy as accuracy, precision, time-to-completion and perceived workload for an assisted neurosurgical simulation task. Participants were found to be significantly slower when using the psychoacoustic sonification as compared to using no aid. Both the spatial and direct sonification showed non-significant tendencies to be slower than the baseline condition. Whilst no significant difference was found between the sonifications, the participants tended to have higher efficacy when using the spatial and direct sonifications, than with the psychoacoustic sonification. Hence these sonifications show the most promise as possible candidates for an auditory feedback system in an extended reality simulator for surgical navigation. However, further evaluation is needed to conclude the full effect of the direct and spatial sonifications on the students’ efficacy. / Utbildningen av kirurgisk navigation för minimalinvasiva neurokirurgiska operationer har historiskt begränsats av flera anledningar. För att kunna lära sig, så har läkarstudenter behövt fysiskt närvara i operationssalen för att observera en lärare genomföra olika operationer. Det har begränsat studenternas möjlighet att få viktig praktisk erfarenhet inom sitt fält. Som ett alternativ till traditionella metoder skulle ett simulationssystem baserat på extended reality (utökat verklighet) och som använder auditiv återkoppling i form av sonifikation kunna användas. Ett sådant system skulle kunna ge läkarstudenter möjligheten att träna praktiskt utanför operationssalen samtidigt som de kan få direkt återkoppling under operationens gång. För att genomföra en första utvärdering av sonifikations påverkan på inlärningen av neurokirurgi när simulationer baserad på extended reality används, så utvecklades en prototyp av en kirurgisk simulator med sex möjliga sonifikationer för uppgiften att positionera en kateter så att den är vinklad i en given riktning. Sonifikationerna byggde på parametrisk mappning baserad på spatiala, psykoakustiska eller direkta metoder. För vardera av de tre metoderna kunde komponent vinklarna antingen kommuniceras parallellt eller sekventiellt. Prototyperna utvärderades mot varandra och basfallet då ingen hjälp användes. Utvärderingen genomfördes som en användarstudie av mixed design (blandad design). Användarnas effektivitet mättes som noggrannhet, precision, använd tid och upplevd arbetsbörda. Deltagarna var signifikant långsammare än basfallet när den psykoakustiska sonifikationen användes. Både den spatiala och direkta sonifikation påvisade en likartad, men icke-signifikanta tendens att va långsammare än basfallet. Medans ingen signifikant skillnad upptäcktes mellan sonifikationerna, så tenderade deltagarna att va mer effektiva när de använde den spatiala och direkta sonifikationerna, i jämförelse med när de använde den psykoakustiska sonifikationen. Därmed verkar dessa två metoder för sonifikation vara de mest lovande kandidater för ett auditivt återkopplingssystem i en extended reality simulator för kirurgisk navigation. Dock behövs vidare utvärdering för att finna en slutsats om spatiala och direkta sonifikationers fulla påverkan på läkarstudenternas effektivitet.

Darśana is an an interactive, multi-channel installation offering participants an artistic, somatic immersion in Hindu mythology. The exhibit interprets the Hindu concept of 'darśana'—a practice involving the experience and observance of a deity—through a contemporary lens. At the heart of the installation is Lord Kṛṣṇa, the beloved flutist deity celebrated for his wisdom and charm. Participants are immersed in a digital rendition of his native forested land, Vṛndāvana. Here, they are encouraged to move, dance, and interact with their surroundings. By presenting ancient stories through new media technologies, "Darśana" explores the potential of modern technology to reinterpret and revitalize traditional practices and beliefs for contemporary audiences, drawing their attention to their cultural heritage. / Master of Fine Arts / Darśana is an an interactive, multi-channel installation offering participants an artistic, somatic immersion in Hindu mythology. The exhibit interprets the Hindu concept of 'darśana'—a practice involving the experience and observance of a deity—through a contemporary lens. At the heart of the installation is Lord Kṛṣṇa, the beloved flutist deity celebrated for his wisdom and charm. Participants are immersed in a digital rendition of his native forested land, Vṛndāvana. Here, they are encouraged to move, dance, and interact with their surroundings. By presenting ancient stories through new media technologies, "Darśana" explores the potential of modern technology to reinterpret and revitalize traditional practices and beliefs for contemporary audiences, drawing their attention to their cultural heritage.

This thesis deals with optimization of sound projectors, based on knowledge on the auditory perception. In sound projection it is desired that the lagging projected sound dominates the localization. One of the most limiting factors here is the leading direct sound, which, however, can only be reduced to a limited extent since the focusing capabilities of sound projectors are physically limited. In order to enable the perception-based optimization, it was therefore essential to gain an understanding of the perceptual role of the direct sound in achieving localization dominance of the projected sound, and which perception-based requirements for sound projection result from this role. A review of existing literature on the perception in scenarios with leading and lagging sound revealed that further insights into lag localization dominance were needed to this end. These insights were gained by conducting several psychoacoustic investigations in an anechoic chamber, reproducing the sounds via individual loudspeakers. Lag localization dominance seemed to be strongly influenced by the temporal characteristics of the playback signal. Afterwards, comprehensive perception-based requirements for sound projection were derived and their consequences for the design of sound projectors were discussed. On this basis, a method for the perception-based optimization was developed with the goal to reduce the influence of the direct sound on localization. This method was named localization masking. Localization masking is based on the additional generation of one or more sounds arriving earlier and from another direction than the direct sound at the position of the listener. An investigation under laboratory conditions, using cascaded lead-lag pairs representing the sounds involved, suggested that localization masking has the potential to achieve that goal. Localization masking enabled the initial lag, representing the projected sound, to dominate the localization up to a 7 dB higher level of the initial lead, representing the direct sound. Finally, localization masking was investigated under realistic conditions. Localization masking was applied to real sound projectors in a real room and proved to work. Localization masking enabled a given projector to be effectively used with a playback signal that requires stronger focusing capabilities. Furthermore, localization masking enabled a projector with less strong focusing capabilities to be effectively used with a given playback signal.