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Assume
a language model P(words)
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Want
P(words|signal).
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If we
had P(signal|words), we could compute the
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words
that maximize P(words|signal). How?
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If
the signal gave us a list of phones, we could do
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this,
but we can't.
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The
best we can do at this point is to compute
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P(words|phones). Then we need P(phones|signal).
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For
this, a hidden Markov model (HMM) is
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used.
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