I appreciate it's just an example, but in my case I'd say they automatically hear humanoids talking in rough voices from the other side of the door, but a decent Perception check would enable them to identify the language as Orcish, allow them to understand what was being said (if they speak Orcish and the conversation was interesting, which it probably isn't) and, with a good roll they'd identify that there are at least 4 creatures taking part in the conversation.
I think this kind of furthers my point though.
Either your ears work or they don't, IRL (at least in my pretty long lived experience - and I have serious ADHD which means I have worse sensory issues than most people), in a static situation like listening at a door. They don't vary in success in a way that RNG reflects. If I am familiar with orcish, it shouldn't be a perception check to identify it,
if I can hear the words, I know what language it is, period. If I can't hear the words, or I'm not familiar with orcish, I don't. External factors (like if people are making noise on my side of the door) may impact it, but it shouldn't really be a roll.
Now let's be clear, part of the problem is the skill design itself, that says: "It measures your general awareness of your surroundings and the keenness of your senses.". That's bad design, frankly. That incredibly overbroad description which encompasses both like, how good hearing and eyesight is, how aware you are generally, and a million other factors is why so many DMs (and adventure designers) call for constant Perception checks. The problem isn't with the DMs or adventure writers - it's with the design of the skill. I'm not saying you're doing it wrong (though I would rephrase the "identify it as orcish" to "hear the words" and then go from the character's backstory - if they have a background where they'll never have heard orcish then no amount of high rolls will let them identify it, though they might be able to repeat the phonemes and have another PC identify it), just that the skill is badly designed.
Even with that, it doesn't seem like this should be rolled - it seems like it should be a passive Perception comparison. I mean, what even is "rolling low on Perception"? Getting distracted? That's simply completely implausible in a lot of scenarios. Equally "rolling high", what exactly is that representing? We can come up with examples but a lot of them are implausible in a lot of scenarios, maybe all of them are in some scenarios - or they just reflect how over-broadly designed it is.
It's also worth noting Take 10 and Take 20 would eliminate some of the weirder issues with Perception (and a bunch of other 5E skills), but 5E doesn't allow for those, and I don't think even suggests them as optional rules (though correct me if I'm wrong).