The present disclosure provides methods, devices and systems for assessing/evaluating the verbal fluency of a user by obtaining a speech (audial/acoustic signal) from a user, detecting disrupted/stuttered and fluent speech time-intervals in the speech, calculating a Disrupted-time value and Fluent-time value based on the disrupted/stuttered and fluent speech time-intervals respectively, and deriving a speech efficiency score for the user/speech based on the Disrupted-time value and Fluent-time value.