No description available.

Purpose: The main objective of the current study was to investigate and monitor the auditory status in a group of adult patients with AIDS receiving antiretroviral therapy (ART) and other therapies in a hospital outpatient clinic in Gauteng, South Africa. Specific objectives included estimating the prevalence of hearing loss and the presence of other otologic effects over and above hearing impairment (tinnitus, aural fullness, disequilibrium, and so forth); assessing the type, degree and configuration of the hearing loss; exploring the type of hearing symptom onset; documenting case history data such as signs and symptoms of each participant and identifying any associations between obtained signs and symptoms and hearing loss; documenting the names of all medications used and their possible impact on hearing function (specifically ototoxicity monitoring of ART); and comparing the results of the experimental group to those of a control group.

The human auditory system can become an active agent in the production of sound when stimulated with specific tone combinations. The resulting auditory distortion products can be amplified and drawn attention to by employing certain just intonation practices – a compositional technique that may serve as a powerful catalyst for reaching different states of mind in listeners. In this thesis, those psychoacoustic phenomena critical to the act of tuning are explored. An experiential tuning protocol is introduced and supported by insights from physiology and neuroscience research. Based on the tuneability of musical intervals, a harmonic framework involving harmonic and subharmonic relationships is analyzed and exemplified via the accompanying composition XV XXVII III XXI IX: Variations. From a phenomenological perspective, the research extends to broader contexts, investigating potential social, ethical, cultural, and political implications of such a practice. / <p><em>XV XXVII III XXI IX: Variations</em> by Luka Aron is a work in 5 parts in which a selected acoustic instrumentation, consisting of bass clarinet, contrabass, euphonium, foghorn organ, harpsichord, serpent, shō, and trumpet coalesces with analog as well as digital synthesis, into one unified mass of sound. By tuning sustained tones towards precision upon occupying the same pitch space, the various timbresare as much canceled out as reinforced, resulting in flux states of spectral fusion. This effect is further achieved through traversing a labyrinth of multiple closely related overtone series, serving as a harmonic framework for the piece’s ever-shifting bedrock. A careful selection of partials is presented, stimulating additional tones in the perception of the listener, making use of a psychoacoustic phenomenon, commonly referred to as otoacoustic emissions, or combination tones. Heavy distortion is then applied to the source signal, allowing the combination tones to materialize in the physical space. Through this, a secondary structure (that, in fact, exposes theundertone series) is gradually unveiled: like light rays meeting the surface of water, partially reflecting back to air, and refracting at once, as they pass from one medium to the other. On a structural plane, the piece stems from complex multi-layered golden mean relationships that permeate to all levels of the composition, ranging from the overall arc to the formal as well as rhythmical aspects of each individual variation, where every sound event is spiraling out of the previous one, and the endpoint is determined right at the initial stroke, before ever unfolding over the total playtime of 43 minutes. With Aron operating the Buchla 200 and EMS VCS3 synthesizers, in addition to the SuperCollider andPure Data coding environments, the cast of musicians includes an array of Stockholm-based artists, such as Mattias Hållsten on shō–a japanese mouth organ–and Susana Santos Silva on trumpet (both members of CC Hennix’ Kamigaku ensemble), just intonation contrabassist Vilhelm Bromander, along with Amina Hocine and her unique self-built foghorn organ. Frequent collaborators Fabian Willmann on bass clarinet and Raphaël Rossé on serpent and euphonium join from the electroacoustic group MINUA, which Aron co-founded. For this occasion, the piece will be diffused on an arrangement of 31 speakers.</p><p><strong>Den klingande delen är arkiverad.</strong></p><p><strong>Luka Aron är artistnam för Luca Aaron Pusch.</strong></p>

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Le réflexe de l’oreille moyenne (ROM) diminue l’énergie acoustique portée par les bruits riches en basses fréquences et de fortes intensités qui pénètrent dans la cochlée. Son déclenchement bilatéral permet ainsi de protéger la cochlée. La perturbation de ce réflexe par des solvants peut accroître les effets cochléo-traumatisants du bruit, notamment chez les salariés du secteur industriel, où bruit et solvant sont souvent associés. L’objectif principal de ces travaux était d’élaborer un test de criblage capable d’identifier les substances volatiles susceptibles de modifier le réflexe. De plus, le choix des solvants nous a permis d’étudier le mode d’action des solvants sur les neurones impliqués dans l’arc réflexe. Pour cela, des rats Brown Norway anesthésiés ont été exposés par inhalation aux solvants aromatiques choisis selon leur lipophilie (log Kow) et/ou selon leur structure. L’amplitude du ROM a été déterminée grâce à la mesure de l’intensité du produit de distorsion acoustique. Les résultats montrent que les effets des solvants sur le ROM sont conditionnés par les paramètres stéréospécifiques des molécules et non par leur lipophilie. Par ailleurs, l’analyse RMN des microsomes de cerveaux de rats confirme que le toluène n’influence pas la fluidité membranaire. En conclusion, le ROM est un bon outil pour détecter des substances dangereuses pour l’audition en cas de co-exposition avec du bruit. De plus, nous pouvons dire que les solvants aromatiques ont une action neuropharmacologique et/ou cochléotoxique qui peuvent retentir de façon distincte sur l’audition des sujets co-exposés au bruit et à des solvants. / The middle-ear reflex (MER) reduces acoustic energy carried by the high intensity noises rich in low frequencies at entering the cochlea. His bilateral trigger thus protects the cochlea. Disruption of this reflex by solvents can increase cochleo-traumatic effects of noise, especially among industrial workers, where noise and solvent are often associated. The main objective of this work was to develop a screening test capable of identifying the volatile substances that could modify the reflex. Moreover, the choice of solvents allowed us to study the mode of action of solvents on the neurons involved in the reflex circuit. For this purpose, Brown Norway rats were anesthetized and then exposed to aromatic solvents selected according to their lipophilicity (log Kow) and/or their structure. The amplitude of the MER is determined by measuring cubic distortion product oto-acoustic emissions. For that, aromatic solvents appear to act directly on the neuronal targets involved in the acoustic reflex circuit, rather than on membrane fluidity. The affinity of this interaction is determined by stereospecific parameters rather than lipophilocity. Additionally, NMR spectra for brain microsomes confirmed that brain lipid fluidity was unaffected by toluene exposure. In conclusion, the MER can be used to detect hazardous volatiles substances for the hearing when co-exposed to noise. Moreover, this study revealed that aromatic solvents have a neuropharmacological and/or cochleotoxic action that can act separately on the hearing of workers exposed to noise and solvents simultaneously.