Я установил xmacro и добавил следующие строки в .lircrc:
begin
prog = irexec
button = KEY_VOLUMEUP
repeat = 1
delay = 2
config = echo KeyStrPress XF86AudioRaiseVolume KeyStrRelease XF86AudioRaiseVolume | xmacroplay $DISPLAY
end
begin
prog = irexec
button = KEY_VOLUMEDOWN
repeat = 1
delay = 2
config = echo KeyStrPress XF86AudioLowerVolume KeyStrRelease XF86AudioLowerVolume | xmacroplay $DISPLAY
end
begin
prog = irexec
button = KEY_MUTE
config = echo KeyStrPress XF86AudioMute KeyStrRelease XF86AudioMute | xmacroplay $DISPLAY
end