Vocal fold models are valuable for studying voice production. They provide an alternative method of studying the mechanics of the voice that does not require in vivo experimentation or the use of excised human or animal tissue. In this thesis, a new method of creating vocal fold models through additive manufacturing is described. The purpose of this research was to reduce model fabrication time, to decrease the number of model failures during manufacturing, and to lay the foundation for creating models with more lifelike geometric and material properties. This research was conducted in four stages. First, a suitable silicone additive manufacturing technique using a UV-curable silicone was chosen. The technique chosen was called freeform reversible embedding (FRE) and involved embedding liquid silicone material into a gel-like medium named organogel. The UV-curable silicone's material properties were identified to confirm its utility in vocal fold model design. Second, an open-source, fused deposition modeling slicing software was selected to create g-code for the printer. Applicable software settings were tuned through qualitative printing tests to find their optimal values for use in FRE printing. Third, 3D-printed cubes were used in tensile tests to characterize the material properties of FRE-printed, silicone material. The cubes were found to be anisotropic, exhibiting different modulus values corresponding to the layer orientation of the printed material. Fourth, vocal fold models were FRE-printed in two different layer orientations and were used in phonation tests to gather data for onset pressure, vibratory frequency, amplitude, and flow rate. The printed models self-oscillated and withstood the strains induced by phonation. These tests showed that layer direction affects the phonation properties of the models, demonstrating that models with layers in the coronal plane had slightly lower frequencies and onset pressures than models with layers in the sagittal plane. The models' onset pressures were higher than what is found in human vocal folds. However, their frequencies were within a comparable range. These tests showed the effectiveness of additive manufacturing in the application of vocal fold fabrication, reducing production effort by allowing researchers to go directly from model design to fabrication in a single manufacturing step. It is anticipated that this method will be modified to incorporate printing of multiple stiffnesses of silicone to better mimic the material properties of vocal fold tissue, and that the anisotropy of 3D-printed material will be leveraged to model the anisotropy of human vocal folds. This work also has potential application areas outside of voice research.

The human voice might have been shaped by sexual selection. Hence, voice fundamental (F0, or pitch) and formant frequencies (Fn, or timbre) are proposed to convey fitness cues germane to rivals and potential mates. First, I confirm the independent effects of F0 and Fn on listeners’ assessments of speaker size, masculinity, and attractiveness. Second, I quantify the just-noticeable differences in both vocal features and then place F0 and Fn cues in conflict by equally discriminable amounts to test their relative influence on such voice-based social judgments. Results revealed a greater relative role of Fn in listeners’ ratings of all three dimensions, suggesting that these dimensions might all be cued more reliably by Fn than F0. Alternatively, given post-hoc principal component analyses that revealed considerable overlap in ratings of size, masculinity, and attractiveness, listeners’ conceptions of these dimensions may not be independent despite a research tradition that assumes they are. / xi, 102 leaves : ill. ; 29 cm

Despite the ongoing global conflicts, wars, disputes and crises which face the world, education is one of the forces enabling global unity. Cultural enrichment, through ‘semesters away,' student exchange programmes and the marketing of ‘ivy-league' education online, have resulted in an explosion in student migration. However, international student migration is not a new concept, dating back to the twelfth and thirteenth centuries in Europe, where foreign students formed communities at recognized universities. The value of global migration in the realm of academics, has gained increasing attention in light of the tremendous value migrant students add to host countries' cultural, political and academic landscapes. However, the largest contribution relates to economic gain, which earns host countries billions of US dollars. While migrant students may be ‘welcome' into host communities, evidence points to issues surrounding homesickness, xenophobia, acculturative stress and social adjustment. One of the largest pull factors in student migration is the issue of university rankings. The University of Cape Town (UCT) is described as the ‘Harvard' of Africa due to its global and local ranking. The institution is ranked 1st in Africa and 136th in the world, in part for its international outlook (staff, students and research collaboration) (Times Higher Education, 2020). It is for this reason that students from across the globe traverse to South Africa to obtain a recognised qualification. The seductive power of UCT as a highly ranked university, exerts a tacit, subtle power over IS. Although there is this academic attraction, student experiences of access, participation and belonging may be questionable. Apart from seductive power, overt power, as seen in the application process for visas, study permits and inflated fees for IS, may create barriers to entry. Migrant student experiences may also be affected by the recent and continued volatility in the higher education landscape. Student mass action, centred on the calls for the #feesmustfall / #rhodesmustfall (‘fallist movements') and calls to decolonise higher education, have taken centre stage in the South African academic landscape. This begs the question of where and how IS fit into the struggle of the host nation. Students' ability to cope and acculturate into the host society is influenced by socio-cultural capital, determined largely by their country of origin (global north versus global south). In this regard IS may experience acceptance or marginalisation based on their social capital or by how they are viewed and accepted by the host nation. Students can also build resilience through assimilation, integration and self- marginalisation. The role of host societies and institutions in assisting migrant students to cope with the acculturation process and culture shock is globally, well documented. This researched is aimed at uncovering issues of access, participation and belonging of IS at the University of Cape Town. The aim of this study was explored by asking the following questions: What are the lived experiences of access, belonging and participation of international students at the University of Cape Town? Sub questions: i. What factors motivated students to migrate to South Africa? ii. How did IS experience and negotiate their experiences during the application process? iii. What were their experiences during registration and orientation? iv. What were their experiences academically and socially? v. How did they negotiate their transition from their home countries to South Africa? vi. What are the differences in experience between IS from varying socio-economic, cultural and geographic backgrounds? This qualitative research, using constructivist grounded theory, sought to uncover the experiences of IS through the lens of inclusive education, power, social capital, acculturation and voice research. Addressing issues of inclusive education is sometimes described as a conundrum in seeking to find solutions to, exactly ‘who is included, and into what?' Research indicates that inclusion is rather a layered, grey area rather than a binary of ‘who is in or who is out?' What inclusive education points to however, is the nature of power between students and institutions. The effects of the various types of power relations on IS are greatly influenced by class, culture, race and origin of students. This study captures the experiences of a cohort of 25 IS from various parts of the world and includes representation from both sexes and varying years of study. Findings of this study, relating to access, participation and belonging within the ambits of inclusive education, indicate varying degrees of inclusion. In the main, the political and geographical nature of the country of origin has a pronounced bearing on the experience of the IS. Similarly, the effects of the seductive power of western, coloniality play an integral role in choice of institution. The South African scenario is further complicated by student unrest/ #fallist movements which further alienates IS.