28-06-2012, 02:37 PM
Speech Recognition
Speech Recognition.ppt (Size: 165.5 KB / Downloads: 162)
Recognition – Conceptually
Data Acquisition
Training Hidden Markov Models for word set
Recognition & Analysis
Viterbi-based Recognition
Calculates the log-maximum likelihood of a series of observations given a particular HMM.
“Which model did this set of data most likely come from?”
Saves time by calculating only a subset of possible paths through the HMM network.
At each new frame, only the most likely transition/observation state pairs are used.
Concepts similar to Dynamic Time Warping
DSP – Recording/Thresholding
Speech Input
Process
Poll A/D for input data (TI-provided code used)
Take only one channel as input
Downsample
Save samples only when signal threshold has been crossed
Lead buffer
Tail buffer
PROBLEMS
Sample transfer modes, single channel selection, threshold values, external microphones
TESTING
Visual and audio inspection in Matlab