1. A terminal apparatus for controlling processing on an interrupt event, based on a priority of a detected operating state of the terminal apparatus and a priority of the interrupt event, after detecting the operating state of the terminal apparatus, when the interrupt event is generated, comprising: a detecting means for detecting changes in use conditions of the terminal apparatus, with a user operation that is not performed for a predetermined period of time being detected as a change in the use conditions of the terminal apparatus; a judging means for judging whether a function accompanied with an audio output is in operation, when changes in the use conditions are detected by the detecting means; and a priority changing means for changing a priority of the function in operation while maintaining the audio output of the function in operation, when the function accompanied with the audio output is judged to be in operation by the judging means, the priority changing means lowering the priority of the function in operation while maintaining the audio output of the function in operation, when the function accompanied with the audio output is judged to be in operation by the judging means, and the priority changing means lowering the priority of the function in operation to the same priority as in an idle state.