What Is an Acoustic Model?

Acoustic models are one of the most important parts of speech recognition systems. Currently, most mainstream systems use hidden Markov models for modeling. The concept of a hidden Markov model is a discrete-time finite-state automaton. The hidden Markov model HMM means that the internal state of this Markov model is not visible to the outside world, and the outside world can only see the output values at various times.