I have successfully got Julius working thanks to the tutorial at VoxForge.

My problem is that it always finds a match. Even if the speech uttered is nothing like anything in the grammar files.

I would like it to return null if there is nothing in the grammar files matching what was said through the microphone.

An alternative to this would be to have Julius use the whole dictionary file rather than just the grammar files. This way it would be able to recognise random sentances etc.

Can anyone let me know if there is a way to achieve the above?

--- (Edited on 5/15/2016 6:07 am [GMT-0500] by ) ---

Good work getting Julius to work correctly.

It sounds like Julius is doing its job right, returning the closest match no matter how badly it matches. Julius will always do this; it assumes that what will be said will be something that it already knows about from the grammar or language model. You can increase accuracy by increasing the number of alternatives in the grammar but you must train your model adequately to recognize these new alternatives. You will note that Julius sends back scores indicating how closely it thought the sound heard matched the solution found. You might be able to get your dialog manager to filter out those that fail to meet a certain standard score threshold.

--- (Edited on 2016-05-15 11:00 am [GMT-0400] by colbec) ---

Thanks Colbec!

Is there a way to use Julius without grammar files? That is, use the dictionary files instead? That way it could listen to any dialect and return a string rather than just what my grammar files have told it?

Also, by dialogue manager I assume you mean the program or app I will be piping the Julius responses to? Or is this a part of Julius I don't yet know about?

--- (Edited on 5/15/2016 4:22 pm [GMT-0500] by ) ---

Julius must have a grammar or a language model to work with. Voxforge provides a tutorial for the grammar approach probably because it is somewhat simpler than the LM, and leads to more positive results in testing, giving the learner a rewarding experience. LMs are a bit looser but Julius requires a lot more tuning to get the same rewards. If the restrictions of Julius are too constraining you might want to examine alternatives such as Kaldi.

Yes, the DM (there are lots of discussions available here on Voxforge) manages inputs and outputs, making decisions to guide the conversation. There are a number of different ways of implementing this, start here on Voxforge (http://www.voxforge.org/home/docs/faq/faq/what-is-a-dialog-manager) and explore the Internet in general.

--- (Edited on 2016-05-16 5:50 am [GMT-0400] by colbec) ---