Generally, `jal toitne, kureotchi, kurehge, kuls`e` are verbal backchannels(VB) which are used by hearer to express their`s sympathy and interaction`s way about speaker`s speech. VB are classified under verbal type and non-verbal type those subsume nod, smile, like as gesture.
If you observed closely multi-corpus, you would find out their`s distribution, sound features, meanings, and degree are different in interactions with speaker and hearer in a dialogue.
VB have various functions. First of all, those express hearer`s agreement with speaker`s speech, and next those are used to express interaction in a dialogue. Lastly, those are ritualistic purpose which help smooth in having talks.