There's a lot of difference between listening and hearing.

The line draws a sharp distinction between the physical act of receiving sound (“hearing”) and the moral or intellectual act of attending to meaning (“listening”). It suggests that genuine understanding requires intention: patience, openness, and a willingness to be changed by what one takes in. In Chestertonian terms, it also hints at the modern habit of mistaking passive exposure for real engagement—being surrounded by talk, news, or argument without actually grasping or considering it. The aphorism works as a rebuke to inattentive conversation and a reminder that communication is cooperative: the speaker may speak clearly, but the listener must actively interpret and respond.