Yeah, but that's really only as part of "strain to hear", in the same way that squinting is "straining to see", which is crucial to the sense.

I think the distinction is that you can physically manipulate/orient your eyes themselves, in ways you cannot do with your ears. You can only turn or raise your head, cup your ear with your hand, or merely concentrate intently. "Prick up one's ears" might be another, if a bit metaphorical, term for this concept.