Real and unreal
They say the road to hell is paved with good intentions. You could paraphrase this and say that the road to bad teaching is paved with good intentions.
A couple of my students have a bee in their bonnet about something they refer to as "real listening". I'd never heard the term before they said it, but I was familiar with the concept: the use of genuine telephone recordings, street noise etc to make listening exercises harder and more lifelike.
The goal is admirable and easy to understand. It certainly appeals to the conscientious teacher, even if the students hate it.
But if you look below the surface, it maybe isn't that good an idea. First of all, in real conversation, any noise or telephone-line interference may be natural, but you will always have recourse to those magic words: "sorry, I didn't quite catch that".
But looking at street noise, we've got to start considering how the human brain and ears work.
In a real-life situation, we can filter out street noise quite effectively. This is not a linguistic skill, it's a much more basic neurological thing. We have two ears. Behind those ears is a sophisticated audio-processing mechanism that compares the input from each, and by comparing differences in timing and volume in the perceived sound, it can take the two one-dimensional signals received by the ear and produce a remarkably accurate three-dimensional image.
It is in producing that image that we naturally (and effortlessly) identify individual sounds. Listening to a recording does not give us the cues that we need to split out the relevant sounds, so it's a much, much harder thing than most of us will need to in our day-to-day lives.
Before anyone says it: yes, a native can listen to a tape with background noise and make out the speech. It may seem only slightly more difficult than doing it face-to-face, but anything that is slightly more difficult for a native is exponentially more difficult for the learner. And it's not something that you can or should force a learner to do -- the native speaker achieves it based on a firm, broad knowledge of the language. This allows the native speaker to fill in the gaps. But it is not a specific skill -- it's an enhancement to the general ability to listen and to infer missing information from the rest of the utterance.
If so-called "real listening" was something we expected people to start on only after they had the phonology and grammar down pat, that would be fine, but I see it as degrading the quality of input for anyone before that.