An audio processing apparatus for a plurality of channels, the audio processing apparatus comprising: a touch panel display device for displaying parameters of audio processing; a plurality of physical operation controllers, each associated with one of the plurality of channels, each of the plurality of physical operation controllers disposed in a respective one of a plurality of channel strips; and a processor configured to detect the operation amount of each of the plurality of physical operation controllers for changing a parameter associated therewith, including: in a first mode, the operation amount of a first parameter for each of the plurality of physical operation controllers for the plurality of channels, wherein said operation amounts are displayed on the touch panel display device in the first mode; and in a second mode, the operation amount of a second parameter for each of the plurality of physical operation controllers for the plurality of channels, wherein said operation amounts are displayed on the touch panel display device in the second mode, wherein the audio processing apparatus further comprises a physical mode operation controller configured to receive user operations of switching between the first mode and the second mode, wherein the processor switches to the second mode upon: the physical mode operation controller receiving a first user operation triggering a parameter window to be displayed on the touch panel display device containing controller icons, followed by one of the controller icons receiving a touch operation for selecting the second parameter to be assigned to each of the plurality of physical operation controllers for the plurality of channels, and wherein the touch panel display device displays the parameter name of the second parameter across the plurality of channels in the second mode. a touch panel display device for displaying parameters of audio processing; a plurality of physical operation controllers, each associated with one of the plurality of channels, each of the plurality of physical operation controllers disposed in a respective one of a plurality of channel strips; and a processor configured to detect the operation amount of each of the plurality of physical operation controllers for changing a parameter associated therewith, including: in a first mode, the operation amount of a first parameter for each of the plurality of physical operation controllers for the plurality of channels, wherein said operation amounts are displayed on the touch panel display device in the first mode; and in a second mode, the operation amount of a second parameter for each of the plurality of physical operation controllers for the plurality of channels, wherein said operation amounts are displayed on the touch panel display device in the second mode, wherein the audio processing apparatus further comprises a physical mode operation controller configured to receive user operations of switching between the first mode and the second mode, wherein the processor switches to the second mode upon: the physical mode operation controller receiving a first user operation triggering a parameter window to be displayed on the touch panel display device containing controller icons, followed by one of the controller icons receiving a touch operation for selecting the second parameter to be assigned to each of the plurality of physical operation controllers for the plurality of channels, and wherein the touch panel display device displays the parameter name of the second parameter across the plurality of channels in the second mode. in a first mode, the operation amount of a first parameter for each of the plurality of physical operation controllers for the plurality of channels, wherein said operation amounts are displayed on the touch panel display device in the first mode; and in a second mode, the operation amount of a second parameter for each of the plurality of physical operation controllers for the plurality of channels, wherein said operation amounts are displayed on the touch panel display device in the second mode, wherein the audio processing apparatus further comprises a physical mode operation controller configured to receive user operations of switching between the first mode and the second mode, wherein the processor switches to the second mode upon: the physical mode operation controller receiving a first user operation triggering a parameter window to be displayed on the touch panel display device containing controller icons, followed by one of the controller icons receiving a touch operation for selecting the second parameter to be assigned to each of the plurality of physical operation controllers for the plurality of channels, and wherein the touch panel display device displays the parameter name of the second parameter across the plurality of channels in the second mode. the physical mode operation controller receiving a first user operation triggering a parameter window to be displayed on the touch panel display device containing controller icons, followed by one of the controller icons receiving a touch operation for selecting the second parameter to be assigned to each of the plurality of physical operation controllers for the plurality of channels, and wherein the touch panel display device displays the parameter name of the second parameter across the plurality of channels in the second mode.