In order to increase the accuracy, the robot should be trained repetitively to identify the right frequency. Moreover, more the training provided, less is the variation. This means that in case of any type of voice modulation or variation, the system will not try to match the perceived signal to many frequencies but will neglect the frequency and won’t perform any action. However, if very few frequencies are matched for a particular variation, it may misinterpret a word or choose a word similar in sound.
It is for this reason that most of the robots with voice recognition system are highly trained by the users. More the robot is trained, quicker is the process of the voice recognition system to identify the word and send a signal to the controlling unit, performing the desired action.