Optimización de estímulos Burst y Pip para terapias de ambiente acústicamente enriquecido y desarrollo de herramientas computacionales para evaluaciones psicoacústicas

The main topic of this final project is about tinnitus, which is a medical condition that already affects to a considerable percentage of the population. Basically, people that suffer from it to a critical level constantly perceive a sound without any source of sound generation corresponding to that perception. This “ghostly” kind of sensation usually manifest itself as a consequence of: excessive exposure to high sound pressure levels, trauma caused by blows, or ototoxycity. Then, it has been common to relate tinnitus directly with hearing loss, without matter of whether or not this is induced by an inadequate overexposure or by a simple presbycusis. Models that, based on experimentation, predict that the perceived pitch of tinnitus it's significantly related with the region of affected frequencies or with the edge of the audiometric curve, have allowed to propose different types of therapies to counteract the sensation. In general, this processes take as a starting point the reconfiguration capacity of the nervous system (homeostatic plasticity) The informatic program for the “Enriched Acoustic Environment” therapy (EAE) takes the subject's audiometric curve as input, and from this generates a sequence of several stimulus (in this case, Burst tones and Pip tones) with amplitudes proportional to the values of loss for each frequency. The program is then consistent with the model of “synchronized neural activity”. However, it was possible to identify drawbacks at the tones generation stage, that affected the constancy for the envelope of each one. Already addressed these shortcomings, a new version of the program was implemented with the appropriate modifications In order to obtain audiometric profiles of subjects an audiometer was developed in Matlab platform under more stringent psychoacoustic criteria, i.e., forced choice method of three alternatives. Further, since the method of equalization of frequency levels for the train of tones implies the hypothesis of “synchronized neural activity”, two psychoacoustic evaluators were developed in order to estimate certain features of tinnitus, and to search for statistical correlations between the approximate variables and the audiometric profile.

• Κύριος συγγραφέας: Larrea Álvarez, César Marcelo (author)
• Μορφή: bachelorThesis
• Γλώσσα: spa
• Έκδοση: 2015
• Θέματα: ENFERMEDAD AUDITIVA; ACÚFENO; REDES
• Διαθέσιμο Online: http://dspace.udla.edu.ec/handle/33000/4474