Proc. SPIE. 5119, Bioengineered and Bioinspired Systems
KEYWORDS: Signal to noise ratio, Digital signal processing, Detection and tracking algorithms, Control systems, Promethium, Biological research, Algorithm development, Acoustics, Automatic control, Prototyping
The knowledge about mechanisms of voice production as well as the parameters obtaining, allow us to present solutions for coding, transmission and establishment of properties to distinguish between the responsible physiological mechanisms. In this work, we are interested in the evaluation of syllabic Sequences in Continuous Speech. We keep in mind this evaluation is very interesting and useful for Foniatrics and Logopaedia applications focus on the measurement and control of Speech Fluency. Moreover, we are interested in studying and evaluating sequential programming and muscular coordination. In this way, the main objective of our work is focus on the study of production mechanisms, model, evaluation methods and introduction of a reliable algorithm to catalogue and classify the phenomena of rythm and speech fluency. In this paper, we present an algorithm for syllabic analysis based on Short Time Energy concept. Firstly, the algorithm extracts the temporary syllabic intervals of speech and silence, and then compared with normality intervals. Secondly, it proceeds to feedback in real time to the patient luminous and acoustic signals indicating the degree of mismatching with the normality model. This methodology is useful to improve fluency disorder. We present an ASIC microelectronic solution for the syllabic analyser and a portable prototype to be used in a clinic level as much as individualized tool for the patient.
Corti’s Organ is an Electro-Mechanical transducer that allows the energy coupling between acoustical stimuli and auditory nerve. Although the structure and funtionality of this organ are complex, state of the art models have been currently developed and tested. Cochlea model presented in this paper is based on the theories of Bekesy and others and concerns on the behaviour of auditory system on frequency-place domain and mechanisms of lateral inhibition. At the same time, present state of technology will permit us developing a microsystem that reproduce this phenomena applied to hearing aid prosthesis. Corti’s Organ is composed of more than 20.000 cilia excited by mean of travelling waves. These waves produce relative pressures distributed along the cochlea, exciting an specific number of cilia in a local way. Nonlinear mechanisms of local adaptation to the intensity (external cilia cells) and lateral inhibition (internal cilia cells) allow the selection of very few elements excited. These transmit a very precise intensity and frequency information. These signals are the only ones coupled to the auditory nerve. Distribution of pressure waves matches a quasilogaritmic law due to Cochlea morphology. Microsystem presented in this paper takes Bark’s law as an approximation to this behaviour consisting on grouped arbitrary elements composed of a set of selective coupled exciters (bank of filters according to Patterson’s model).These sets apply the intensity adaptation principles and lateral inhibition. Elements excited during the process generate a bioelectric signal in the same way than cilia cell. A microelectronic solution is presented for the development of an implantable prosthesis device.