the number of states

[Jiahn K]

why do traditional HMMs for ASR tend to model each phone with three distinct states?
I think simply using loop would be enough to control the duration?

[Simon]

The three states allow the model to capture sound changes within a phone – the “beginning”, “middle” and “end”. Any number of emitting states could be used, but 3 has been found to work well and is – as you correctly state – the most common choice.

[Author]

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