How can we teach english pronunciation to the students? I think the answer to this question is somehow relative for it can neither be white nor black. If someone decides to learn a L2, English in that case, it is because they have some motives behind it. One of the possible reasons could be for communication purposes both with natives or non-natives.
That means the learner wants to understand when either natives or non-natives use English for communication or else be able to express themselves in a way that they could be understood by “the others” easily. “The others” in this case refers to either natives or non-natives, or even both.
This has to do with the personal objective. If one does not have any intention of interacting with the natives other than non-natives, then teaching RP as a model could be the answer. However, if one has to interact with natives, then, limiting oneself to learning RP should not be recommended as RP only serves not as the end by itself, but as a gateway to advanced English pronunciation as it is used in real English, and by most natives. In the other hand, expand the teaching model can help them improve the students listening.
Teaching RP should serve as a base, or introduction to Standard English Pronunciation taught at low levels due to variation of accents among native speakers. By low levels, I mean it is upon each teacher to evaluate and decide up to what level they need to apply RP as an introduction to teaching pronunciation, and then from there onwards, help learners go beyond RP so as to interact effectively with the natives using real English.
Most of the learners who want to practise English conversation go for the native teachers. This has made learning English as a L2 prioritise native teachers as they are claimed to be more authentic especially when it comes to speaking. However, the question comes as to how authentic linguistically those natives are.
If I were to recommend a model native speaker to the learners, who would I go for? In addition to that, what happens to learners in such cases whereby they find themselves in constant changes of L2 teachers and from diverse origins? Who would they choose as their model?
Would it be recommendable to teach RP?
If so, would that RP pronunciation help them achieve their objective? One of the greatest challenges for English learners is that they find it difficult to understand natives. They can understand other L2 speakers (non-natives) easily but when it comes to real English with natives, that makes them feel frustrated.
Personally, I think one of the problems could be that during the English course, learners end up not being exposed to real English pronunciation. They are taught RP but when they come out of the class to face the real world, something they were not aware of, only to discover that the RP is only used inside the four walls of the classroom.
That being the case, the english teacher is somehow to blame for their failure in understanding real English as he or she never helped them know that English Pronunciation does not end up in RP, but it goes beyond there.
One thing is the standard pronunciation that nobody uses in the real world (BBC English) and the other one is the utility of the language as far as International communication is concerned. We need to teach learners something that will serve them in the real world when it comes to communication competency.
Instead of teaching RP, personally, I would opt for the combination of Standard British English and Standard American English as a model for the learners. The issue of regional accents is something else, which should be treated differently.