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State-of-the-art cochlear implants perform a frame-based signal processing on the incoming audio signal with a fixed frame-size. In the end of the signal processing chain, a stimulation pattern is generated for the current frame. As a consequence, the electrodes in the array are stimulated with a fixed rate independent of their frequency bands. In other words, the stimulation rate is dependent on and mostly equal to the frame rate of the incoming audio frames. In the context of the ABCIT (Advanced Binaural Cochlear Implant Technology) project, we have developed a research interface for cochlear implants (Adiloglu et.al. IWAENC 14), which is now being extended with a capability to stimulate at a variable rate. Different methods of adapting the stimulation rate depending on the input signal are possible and will be evaluated with subjects in the future. One possible strategy to adapt the stimulation rate depends on fundamental frequency (F0) tracking. Here, we present how the adaptive stimulation part has been implemented and present first objective measurement results. [ABSTRACT FROM AUTHOR]

Using current speech processors, Cochlear Implant (CI) users already reach up to 100% speech intelligibility in quiet. Listening in noisy environments however, still remains a challenge. The increasing supply of profoundly deaf patients with two independent implants (bilateral supply) already provides improved speech intelligibility in noise compared to unilateral supply. In this study, the potential of binaural speech enhancement strategies to further improve speech intelligibility of bilaterally implanted CI users in noise was assessed. Instrumental measures as well as perceptual (listening) tests were used to evaluate 2 monaural and 6 binaural noise reduction schemes. All algorithms were implemented in the Master Hearing Aid framework and run online in real-time. 4 spatially distinct noise scenarios were created in a reverberant environment (T60 ≅ 1250 ms) using virtual acoustics. The Oldenburg matrix sentence test (Oldenburger Satztest OLSA) was used as speech material. Several instrumental measures were applied to evaluate the algorithms' potential in improving speech intelligibility independent of inter-subject variability. Results from this instrumental evaluation demonstrate the ability of the tested algorithms to provide improvements in speech intelligibility as well as sound quality. For the perceptual evaluation, speech reception thresholds (SRT50) were determined using a maximum likelihood adaptive measurement procedure. 8 bilaterally implanted CI subjects, using processors from 3 different manufacturers have participated in the evaluation. The results show substantial and significant improvements in perceptual speech reception threshold (SRT50) in reverberant, spatial testing conditions using the algorithms presented here. [ABSTRACT FROM AUTHOR]

Many societies across the world are confronted with demographic changes, usually related to increased life expectancy and, often, relatively low birth rates. Information and communication technologies (ICT) may contribute to adequately support senior citizens in aging societies with respect to quality of life and quality and efficiency of health care processes. For investigating and for providing answers on whether new information and communication technologies can contribute to keeping, or even improving quality of life, health and self-sufficiency in ageing societies through new ways of living and new forms of care, the Lower Saxony Research Network Design of Environments for Ageing (GAL) had been established as a five years research project, running from 2008 to 2013. Ambient-assisted living (AAL) technologies in personal and home environments were especially important. In this article we report on the GAL project, and present some of its major outcomes after five years of research. We report on major challenges and lessons learned in running and organizing such a large, inter- and multidisciplinary project and discuss GAL in the context of related research projects. With respect to research outcomes, we have, for example, learned new knowledge about multimodal and speech-based human-machine-interaction mechanisms for persons with functional restrictions, and identified new methods and developed new algorithms for identifying activities of daily life and detecting acute events, particularly falls. A total of 79 apartments of senior citizens had been equipped with specific "GAL technology", providing new insights into the use of sensor data for smart homes. Major challenges we had to face were to deal constructively with GAL's highly inter- and multidisciplinary aspects, with respect to research into GAL's application scenarios, shifting from theory and lab experimentation to field tests, and the complexity of organizing and, in our view, successfully managing such a large project. Overall it can be stated that, from our point of view, the GAL research network has been run successfully and has achieved its major research objectives. Since we now know much more on how and where to use AAL technologies for new environments of living and new forms of care, a future focus for research can now be outlined for systematically planned studies, scientifically exploring the benefits of AAL technologies for senior citizens, in particular with respect to quality of life and the quality and efficiency of health care.