BATTERY PACK

A battery pack includes a battery cell and a casing configured to receive the battery cell. The casing has a vent hole configured to allow gas generated in the battery cell to be discharged therethrough, and a sound generator installed in the vent hole so as to block the vent hole. The sound generator is configured to allow the gas to pass therethrough, and generate a sound by the flow of the gas when the gas is discharged from the casing through the vent hole.