Over the years, while coaching students who attend teacher training courses in Buenos Aires, and even some graduate teachers and translators, I have noticed that the students had trouble identifying tone and more often than not, could hardly make any sense of what they were doing.
First of all, we need to agree that all the theory and notation systems must be regarded as conventions, approximations, that attempt to describe and reflect current RP or GA speech. Some systems are quite accurate at setting down the various differences in pitch, while others either oversimplify their description or bury it in a confusing jumble of theoretical terms that puzzle students. Even though they manage to study and pass their exams, they are unable to use intonation spontaneously and often end up hating the subject.Most of the problems arise from the fact that teachers usually give their students different intonation textbooks, written by different authors, some older and some more recent. Generally, they use one for reading and speaking practice or for laboratory work, and another two for theory. However, each of these authors has their own notation system and even assigns different names to the tones. Some consider the stressed syllables in the middle of longer sentences while others totally neglect them.What's worse is that they even differ on basic concepts, such as the intonation of yes-no questions in RP.
In my opinion, the solution is for teachers to bring their material up to date and compare older books and recordings with current ones and point out that languages change, as is the case with English.
RP: Received Pronunciation, the acceptable social standard for British English.
GA: General American, the most widespread American accent, considered standard.
I have always held that the best approach for ESL learners is common sense. This holds good both for students of ESL and for those who are studying to become teachers, translators or interpreters. It is true that intelligibility matters more than accent, especially for those who need theirEnglish for business, in a multilingual and multicultural setting. However, teachers and prospective teachers have to be more discrimminating and industrious when it comes to accent reduction. This leads us to the question of which variety of English and accent we will use. In Argentina, there is still a deeply entrenched conservative tradition of teaching only RP (and often an outdated variety) thoroughly banning American English, as something to be avoided. Actually, in the business world, sticking to GA would make more sense because there are many more American companies, banks, universities, TV shows and movies than British ones. I wish to point out, though, that I'm referring to a standard American accent, as spoken my the majority of educated Americans who don't use a regional accent. By the same token, if we choose a British accent, the choice is the so-called "prestige dialect", i.e. RP. However, there has been much more change in RP than in GA in the last few decades, which is a fact that is generally disregarded by teachers in Argentina, who still seem to be in denial. Additionally, we must admit that the highly-touted and revered RP is not spoken by the majority of British speakers, but by a minority who lives in part of London and the Southeast of England. In fact, there are more speakers of Northern English, as the North of England is more populated than the South. Besides, one relatively recent addition to the major English accents is Standard Australian, which is becoming more widespread and has definitely broken into the English teaching market.
At any rate, while it is practical an desirable to stick to a major standard in language, the importance and need for RP has been vastly overrated. It is no longer necessary to speak "BBC English" to read the news on TV in the U.K., and the more refined, conservative varieties of RP have become more unpopular in the last two decades or so. Unfortunately, the ESL teaching world in Argentina, where society in general tends to dwell on the past, would gladly have all students speak like the characters in The King's Speech.