A method for implementing an intelligent sleep mode on an electronic apparatus includes the steps of: tracking an elapsed time where no operational input is received; decreasing output volume when the tracked time is equal to a predetermined time period if the output volume is greater than a predetermined volume; and turning off the electronic apparatus when satisfying a predetermined requirement, wherein the predetermined requirement may be that the current volume is equal to or less than the predetermined volume or that a time tracked by the time reaches the second predetermined time period. A related electronic apparatus is also disclosed.