I came across an essay called "De Auditu" ("on listening to lectures"), by Plutarch, the Greek Historian and Essayist, who lived nearly 2000 years ago. It's worth a read, if only to recognize how timeless his words are.
In the essay, Plutarch begins by noting that it is just important to consider and learn how to listen as it is to learn how to offer a discourse. He urges the listener to be patient, to focus on substance not style. He recommends moderation in posing questions, including limiting one's questions to the area of the speaker's expertise. He suggests that even errors in lectures offer opportunities for learning, by motivating introspection into one's own ways of thinking:
Where [the speaker] is successful we must reflect that the success is not due to chance or accident, but to care, diligence, and study, and herein we should try to imitate him in a spirit of admiration and emulation; but where there are mistakes, we should direct our intelligence to these, to determine the reasons and origin of the error. For as Xenophon asserts that good householders derive benefit both from their friends and from their enemies, so in the same way do speakers, not only when they succeed, but also when they fail, render a service to hearers who are alert and attentive.He describes an ideal listener's demeanor:
Finally, the following matters, even with speakers who make a complete failure, are, as it were, general and common requirements at every lecture: to sit upright without any lounging or sprawling, to look directly at the speaker, to maintain a pose of active attention, and a sedateness of countenance free from any expression, not merely of arrogance or displeasure, but even of other thoughts and preoccupations. Now in every piece of work, beauty is achieved through the congruence of numerous factors, so to speak, brought into union under the rule of a certain due proportion and harmony, whereas ugliness is ready to spring into being if only a single chance element be omitted or added out of place. And so in the particular case of a lecture, not only frowning, a sour face, a roving glance, twisting the body about, and crossing the legs, are unbecoming, but even nodding, whispering to another, smiling, sleepy yawns, bowing down the head, and all like actions, are culpable and need to be carefully avoided.
He urges listeners to apply themselves and think critically about what they hear:
... let us urge them that, when their intelligence has comprehended the main points, they put the rest together by their own efforts, and use their memory as a guide in thinking for themselves, and, taking the discourse of another as a germ and seed, develop and expand it. For the mind does not require filling like a bottle, but rather, like wood, it only requires kindling to create in it an impulse to think independently and an ardent desire for the truth. Imagine, then, that a man should need to get fire from a neighbour, and, upon finding a big bright fire there, should stay there continually warming himself; just so it is if a man comes to another to share the benefit of a discourse, and does not think it necessary to kindle from it some illumination for himself and some thinking of his own, but, delighting in the discourse, sits enchanted; he gets, as it were, a bright and ruddy glow in the form of opinion imparted to him by what is said, but the mouldiness and darkness of his inner mind he has not dissipated nor banished by the warm glow of philosophy.The oft-quoted phrase "For the mind does not require filling like a bottle, but rather, like wood, it only requires kindling" appears here. (It is often mis-attributed to William Butler Yeats in a modified form: "Education is not the filling of a pail but the lighting of a fire.") With these words, he gets to the very heart of what it means to truly learn. We can only learn when we are motivated and fully engaged in the learning process. Passive listening is not beneficial.
Modern constructivist education models have sought to reduce the role of lectures in the classroom, to move the role of the teacher from being a "sage on the stage" to a "guide on the side", in part because the art of listening is lost in students who are forced to listen to too many lectures, for years and years. But given that there are still many classes that rely on traditional lectures, and even flipped classrooms require listening to taped lectures outside the classroom, it would behoove students to reflect upon Plutarch's advice and ponder the difference between listening as "bottle-filling" and listening as "fire-kindling".