Sound with a tap

I am new to CODEA and Lua as a whole. I was trying to make something and I can’t seem to find something. I was just wonder what I could to to have the program to make a sound when I tap the screen. I can’t seem to figure it out.

function touched(t)
    if t.state==ENDED then --play sound when tap stops
        sound(SOUND_POWERUP)
        --or
        sound( "A Hero's Quest:Arrow Shoot 1" )
        --a longer one
        music( "A Hero's Quest:Battle" )
    end
end