Handling non-speech events in Alex¶
The document describes handling non-speech events in Alex.
The ASR can generate either:
- a valid utterance
- the ```` empty sentence word to denote that the input was silence
- the _noise_ word to denote that the input was some noise or other sound which is not a regular word
- the _laugh_ word to denote that the input was laugh
- the _ehm_hmm_ word to denote that the input was ehm or ehm sounds
- the _inhale_ word to denote that the input was inhale sound
- the _other_ word to denote that the input was something else that was lost during speech processing approximations such as N-best list enumeration or when the ASR did not provided any result. This is because we do not know what the input was and it can be both something important or worth ignoring. As such, it deserves special treatment in the system.
The SLU can generate either:
- a ordinary dialogue act
- the null() act which should be ignored by the DM, and the system should respond with silence()
- the silence() act which denote that the user was silent, a probably reasonable system response is silence() as well
- the other() act which denote that the input was something else that was lost during processing
The SLU should map:
- ```` to silence() - silence will be processed in the DM
- _noise_, _laugh_, _ehm_hmm_, and _inhale_ to null() - noise can be ignored in general
- _other_ to other() - other hypotheses will be handled by the DM, mostly by responding “I did not get that. Can you ... ?”
The DM can generate either:
- a normal dialogue act
- the silence() dialogue act
The DM should map:
- null() to silence() - because the null() act denote that the input should be ignored; however there is a problem with this, read the note below for current workaround for this
- silence() to silence() or a normal dialogue act - the DM should be silent or to ask the user “Are still there?”
- other() to notunderstood() - to show the user that we did not understood the input and that the input should be rephrased instead of just being repeated.
PROBLEM As of now, both handcrafted and trained SLUs cannot correctly classify the other() dialogue act. It has a very low recall for this DA. Instead of the other() DA it returns the null() DA. Therefore, the null() act is processed in DMs as if it was the other() DA for now.