Publications by authors named "Louis Pisha"

Most systems for simulating sound propagation in a virtual environment for interactive applications use ray- or path-based models of sound. With these models, the "early" (low-order) specular reflection paths play a key role in defining the "sound" of the environment. However, the wave nature of sound, and the fact that smooth objects are approximated by triangle meshes, pose challenges for creating realistic approximations of the reflection results.

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Convincing simulation of diffraction around obstacles is critical in modeling sound propagation in virtual environments. Due to the computational complexity of large-scale wavefield simulations, ray-based models of diffraction are used in real-time interactive multimedia applications. Among popular diffraction models, the Biot-Tolstoy-Medwin (BTM) edge diffraction model is the most accurate, but it suffers from high computational complexity and hence is difficult to apply in real time.

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We have previously reported a realtime, open-source speech-processing platform (OSP) for hearing aids (HAs) research. In this contribution, we describe a wearable version of this platform to facilitate audiological studies in the lab and in the field. The system is based on smartphone chipsets to leverage power efficiency in terms of FLOPS/watt and economies of scale.

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Hearing loss is one of the most common conditions affecting older adults worldwide. Frequent complaints from the users of modern hearing aids include poor speech intelligibility in noisy environments and high cost, among other issues. However, the signal processing and audiological research needed to address these problems has long been hampered by proprietary development systems, underpowered embedded processors, and the difficulty of performing tests in real-world acoustical environments.

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