A numerical controller, wherein an operator, even remotely, can recognize a sound of a machine tool or the like, and can intuitively know the effect in adjusting the parameter. The numerical controller includes a drive axis controlling part configured to control a drive axis; a drive axis data storing part configured to obtain a physical quantity of the drive axis as time-series data and store the time-series data; a displaying part configured to convert the time-series data into a predetermined indication form and display the data as at least one displayed waveform; a selecting part configured to select the displayed waveform by input operation of the operator; a sound converting part configured to convert the selected waveform into sound conversion data, a type of which is capable of being output as sound; and a sound outputting part configured to output the generated sound conversion data as sound.