Abstract: An information processing apparatus includes: a power supply for supplying a power; a sound collector for collecting a noise caused by the surroundings to output a sound volume; a sound volume recognizer calculated a measuring value from the sound volume to compare the measuring value with a reference value and output a revolution control signal and a sound level signal; a voltage controller for controlling the power supplied from the power supply in response to the revolution control signal; a blower having a fan rotated with the power supplied from the power source to cool inside the apparatus; an operation setting unit for producing and outputting an operational signal indicative of a processing rate in response to the sound level signal; and a central processing unit changed the processing rate in accordance with the operational signal to perform operation, thereby controlling the number of revolution of the blower in response to a noise and the processing rate of the central processing unit to restrain c