An apparatus comprising: an audio processor configured to process audio; and a controller configured to control the audio processor to, in response to an event to change a volume level of the output audio: separate an input audio into a first audio component and a second audio component, wherein the first audio component comprises a voice, and the second audio component comprises a background audio, output audio: change the volume level of the output audio, and change a ratio of the first audio component to the second audio component in the output audio according to the changed volume level of the output audio, wherein the controller is configured to control the audio processor to change the ratio of the first audio component by increasing a proportion of the first audio component compared to the second audio component based on the changed volume level being smaller than a first volume, increasing a proportion of the second audio component compared to the first audio component based on the changed volume level being larger than a second volume, and not changing the ratio of the first audio component to the second audio component based on the changed volume level being between the first volume and the second volume, and wherein the second volume is larger than the first volume. an audio processor configured to process audio; and a controller configured to control the audio processor to, in response to an event to change a volume level of the output audio: separate an input audio into a first audio component and a second audio component, wherein the first audio component comprises a voice, and the second audio component comprises a background audio, output audio: change the volume level of the output audio, and change a ratio of the first audio component to the second audio component in the output audio according to the changed volume level of the output audio, wherein the controller is configured to control the audio processor to change the ratio of the first audio component by increasing a proportion of the first audio component compared to the second audio component based on the changed volume level being smaller than a first volume, increasing a proportion of the second audio component compared to the first audio component based on the changed volume level being larger than a second volume, and not changing the ratio of the first audio component to the second audio component based on the changed volume level being between the first volume and the second volume, and wherein the second volume is larger than the first volume. separate an input audio into a first audio component and a second audio component, wherein the first audio component comprises a voice, and the second audio component comprises a background audio, output audio: change the volume level of the output audio, and change a ratio of the first audio component to the second audio component in the output audio according to the changed volume level of the output audio, wherein the controller is configured to control the audio processor to change the ratio of the first audio component by increasing a proportion of the first audio component compared to the second audio component based on the changed volume level being smaller than a first volume, increasing a proportion of the second audio component compared to the first audio component based on the changed volume level being larger than a second volume, and not changing the ratio of the first audio component to the second audio component based on the changed volume level being between the first volume and the second volume, and wherein the second volume is larger than the first volume. change the volume level of the output audio, and change a ratio of the first audio component to the second audio component in the output audio according to the changed volume level of the output audio, wherein the controller is configured to control the audio processor to change the ratio of the first audio component by increasing a proportion of the first audio component compared to the second audio component based on the changed volume level being smaller than a first volume, increasing a proportion of the second audio component compared to the first audio component based on the changed volume level being larger than a second volume, and not changing the ratio of the first audio component to the second audio component based on the changed volume level being between the first volume and the second volume, and