- Augmented sound communication systems based on unsupervised optimization theory
- In many cases, acoustic signal processing deals with data that can be observed only just one time. This is because propagation of acoustic waves strongly depends on a sound field and spectral structures of the sound source. Thus, it is required to establish a framework that treats not “big data” but “small data.” For this reason, we are addressing blind (unsupervised) theories, e.g., independent low-rank matrix analysis and, sparse tensor decomposition. Also, we aim to build some applications of acoustic signal processing including a human-robot interface and universal communication-supporting systems.
- Mathematical analysis and sensibility quantification for non-linear signal processing
- Non-linear audio signal processing is applied to many tasks nowadays. In recent years, it is revealed that lower- and higher-order statistical space have a hysteresis property, which provides the fixed point of a human auditory impression. On the basis of this finding, we are pursuing the meaningful statistical estimation for humans and produce a new beneficial framework of signal processing.
- User-oriented and music signal processing
- We aim for developing high-quality music signal processing by applying machine learning theories to various multidimensional music data. Also, user-oriented systems for music signal analysis are addressed to contribute to built a new artistic production from the engineering view.
- Inverse problems for acoustic field
- We tackle with inverse problems for acoustic field, such as sound field imaging, analysis, source localization, and estimation of room acoustic parameters. We pursuit new methodologies with various approaches (optimization, machine learning, etc.) and develop systems to achieve these purposes.
- Signal processing for sound field recording, transmission, and reproduction
- We deal with a broad range of problems for sound field recording, transmission, and reproduction. By using these methodologies, we develop new systems for telecommunication, virtual reality, and so on.
- Augmented speech communication using speech synthesis and conversion
- Utilizing machine-learning-based speech synthesis and conversion, we realize augmented speech communication beyond differences among AI and human beings.