A little anecdote to start this off, as my head is trying to work out exactly where this post is going…
I’ve been teaching Trinity preparation courses for a couple of years in a centre where I’m also the coordinator of the classes, so I know quite a lot of the learners (who are all adults and teachers themselves) either through having taught them, or having spoken to them about exams or popped into their classes to talk to their teachers. This year, one of the classes is being taught by an American and (seriously) a couple of the learners asked me whether they would have problems in their exam (i.e. be marked down) if they spoke with an American accent!
One of the ideas behind the native=best idea is that native speakers are better placed to model the language being taught and, more often than not, this boils down to accent. But what is a “native” speaker accent? Think about how the RP pronunciation of ‘bus’ differs to how someone from Yorkshire might say the word, or how someone from Glasgow might say ‘book’, or how a Texan might say ‘twenty’. There’s a number of fabulous videos on Youtube in which people speak with different regional accents and although most online dictionaries limit phonetic spellings to RP or a standard American accent, Pearson continue to produce revised editions of their Pronunciation Dictionary which gives the most frequently used alternatives.
An aspect of teaching different accents is the use of the phonemic chart as, whilst versions of the chart exist, the one most commonly used in Europe contains the sounds associated with an RP accent, meaning that some teachers struggle to transcribe their own variations of words. Another aspect of the chart which often scares teachers is that their learners will be more familiar with it than they are! This is almost certainly true for teachers whose mother tongue is English, as they will have learnt to identify different vowels sounds through practice and, although have probably noticed the weird squiggly letters in the dictionary, have never needed to engage with phonetics.
I recommend reading Adrian Underhill’s article on the Humanising Language Teaching blog, Pronunciation: the Cinderella of Language Teaching and have a listen to The TEFL Show’s podcasts, hosted by Marek Kiczkowiak and Robert McCaul, on teaching vowel and consonant sounds as well as the episode “Which pronunciation model should we teach?”