Accent conversion: Learners of a second language practice their pronunciation by listening to and imitating utterances from native speakers. Recent research has shown that choosing a well-matched native speaker to imitate can have a positive impact on pronunciation training. Here we propose a speech-modification technique that can generate utterances with the vocal properties of the learner and the accent of a native speaker. This is accomplished by altering both prosodic and segmental characteristics of speech. Our results indicate that the technique can reduce foreign accentedness without significantly altering the voice-quality properties of the foreign speaker.

Speech exaggeration: The objective of this work is to develop speech processing tools that can highlight spectral differences between similar phonemes. Such tools have application in second-language (L2) learning. Take the case of Japanese speakers, who have trouble discriminating /r/ from /l/ English phones (e.g., 'rock' vs. 'lock') because such contrast does not exist in their native language. Emphasizing spectral differences between these phonemes can help the L2 learner focus on those spectral cues that carry discriminatory information.

Infrared spectroscopy: The objective of this research is to develop a low-cost infrared absorption spectroscope based on linear variable filters. This instrument represents an alternative to electronic-nose devices based on cross-selective gas sensor arrays. Instead, the proposed instrument uses the concept of computational “pseudosensors,” where spectral lines in an analytical instrument are clustered into groups and used as independent variables. At the core of our system is an IR detector that combines an LVF and an array of 64 pyroelectric detectors (IR Microsystems). The LVF is a wedge-shaped interference filter, which provides a bank of transmission wavelengths from the thinnest end (short wavelengths) to the thickest (long wavelengths). The LVF sits atop a 64-pixel pyroelectric detector array, which produces a low-resolution spectrum of the transmitted spectra. Because of its particular bonds and molecular structures, each chemical species produces a unique IR spectrum, which can be used for analytical purposes.

Omnidirectional imaging: We have developed a computational range sensor based on ominidirectional vision. The device employs a structure-from-motion strategy, where depth information is extracted from optical flow. These range estimates are then used to build a probabilistic map by means of certainty grids.