Hola Todos!!!!

I am from Colombia’s capital, Bogotá and despise all the unfavorable press we get the country has a lot of really nice things to offer: all the weathers, good food, lots of fruits, the best coffee in the world, beautiful sightseeing and wonderful people.

I graduated as an Electronic Engineer and a have worked in process control and automation for some time, but as I did my undergraduate final project in quality control via machine vision, I became interested in this field and found the VIBOT master, which has been one great life and academic experience.

I am interested in acquiring job experience in this field but also in pursuing further academic formation, specially in the field of medical imaging and/or human perception but also in the robot localization and navigation, so if you are looking for good “fella” I’ll be happy to join you and put some tropical warm in. Check my CV to know with more detail about me.

Current approaches for exploiting the ability of the auditory system as a mean to transmit information address the issue of audio as a source of information only to the point of using it as an auxiliary channel or restrict it to environments based on computer graphical interfaces, which limit the complete capability for conveying information about the surroundings. The current project is aimed to tackle this from a different perspective.

The overall objective of this project is to propose, implement and evaluate a system that explores the possibility of supplying auditory information that resembles the one provided by the visual system (in case of its absence), making it feasible for a visually impaired person to navigate in a real environment such as a room.

In order to do so, the relevant aspects of the auditory system with respect to perception are reviewed, the binaural interaural sound perception and the spatialized sound perception models are described and implemented in order to determine the validity and the pertinence of the models within the context of the project. To take advantage of the auditory system, the nature of sounds and the models for information mapping namely earcons and auditory icons, were also reviewed, guidelines were drawn from the studies that have been done on the subjects and sets of sounds were used.

With a certain understanding of the auditory models and the sounds which would transmit the information, a system that could take advantage of the auditory system is proposed where by combining a basic video processing block that extracts lateral coordinates from visual markers in a scene, transforming them into azimuth angles and using the model of the Head Related Transfer Function to convolve the modeled monophonic sound source signal, a spatialized version of the created earcons is presented to the user.

The system and its different parts are tested in two separate stages with the purpose of assessing the proposed blocks, sounds, schemes and delays, and findings confirming the limitations of the HRTF and the challenges of the sound sources design as well as the formulation of subject based tests were made.

The HRTF model and its main feature the ``out of the head perception of localization'' was confirmed as well as the front/back confusion consequence of the non-individualized function, was observed.
Earcons were found to be better as a coding scheme for spatialized sounds.
Small delays between sounds when several sources are presented improve significantly the ability to localize individual sources.
Overall the problem tackled seems to have a good or at least, interesting possibilities of developing new concepts for aiding tools for visually impaired people.

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• Thesis
• Poster
• Paper

Mario A. Rojas Q.         marioarojasq@gmail.com

Prof Andrew Harvey     A.R.harvey@hw.ac.uk