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Speech and Audio Processing

Research themes in CVSSP Multimedia:
[ Articulatory ASR | Acoustic scene analysis | Time-frequency | Audio classification | People & Projects ]


Articulatory gestures for speech recognition

Using information about the movements people make when producing speech, this kind of approach to automatic speech recognition promises to provide improvements in accuracy over conventional systems, particularly for fluent or conversational speech or in the presence of noise.
sagittal-view of a speaker

Time-frequency analysis

It is typical to perform some sort of short-term frequency analysis of time-varying signals, but there are high-resolution transformations and adaptive filtering methods that can give better definition of certain features in an audio signal. One application of this is in speech coding.
CVSSP waveform  
CVSSP spectrogram speech file
cvssp.wav

Audio classification

Classification is an important task when it comes to information retrieval, or trying to index a lot of material, e.g., from TV broadcasts. Research in the group has sought to identify certain characteristics or "events" from the audio stream with a view to enhancing the amount of meaningful data that can be used for tagging.

Periodic-aperiodic decomposition of speech signals

Many speech sounds contain contributions both from voicing in the larynx and from air-turbulence noise. We use a signal processing technique, called the pitch-scaled harmonic filter, to try to separate these two components so that they can each be analysed separately. Such acoustic scene analysis has also been shown to help in other applications of speech processing.
spectrograms


People

Staff

Research students

Former members

  • Dr Edward Gatt
  • Dr Hossein Marvi
  • Dr Sanjeev Sarpal
Audio mixer

Projects

  • Dynamic faces - understanding the dynamics of real faces
  • Dansa - Statistical models to relate speech gestures to meaning
  • Columbo - Harmonic decomposition applied to automatic speech recognition


[ Articulatory ASR | Acoustic scene analysis | Time-frequency | Audio classification | People & Projects ]

© 2002-5, maintained by Philip Jackson, last updated on 20 May 2005.