Well, this seems to be the blog for more cognitive topics. If you want a more clearly sociocultural flavour (at the moment), better turn to the Facebook page. However, the way we sound when we talk is, in fact, a highly important aspect of our identity to host people. Each of us will always have an accent (not just in speaking, but right across the board, in our hearing, our understanding of words, the inferences we draw, the grammatical form of our utterances) which will be such a part of who each of us will be.
I remember as a nineteen-year-old thinking that articulatory phonetics was the magic bullet for quickly achieving accent-free speech. Decades later, I studied speech perception, and found out that matters were more complicated than my articulatory phonetics teachers realised. You don't get to hear whatever you want hear. Rather, your mother-tongue listening system strongly influences what you hear when you listen to host speech. Granted, host speech does "clear up" a lot over the early days and weeks, and pronunciation does improve a lot over the first six months or a year.
Language courses that try (in vain) to be exhaustive with all the articulatory phonetics are not in the spirit of the GPA. Too much time is spent talking about "retroflex voiceless aspirated stops" and on and on and on. The GPA tries to minimise the intellectualisation/academicisation of growing participation.
It is in the GPA spirit to give a name to "retroflex voiceless aspirated stops", either a familiar host word that starts with a "retroflex voiceless aspirated stop," for example, ThanDa, 'cold', or a gesture representing that word, such as a shivering motion with one's arms torso and head. In this manner, the nurturer and GPs come to have a set of shared names for troublesome sounds--increasing the closeness of their personal relationship, unlike "retroflex voiceless aspirated stops," which increases the distance in their impersonal relationship!
Now the GP hears a new word, say, Thosna 'stuff, cram', and to confirm that she heard it right, she makes that shivering motion. Or if the GP badly mispronounces a word, the nurturer makes the shivering motion, to tell the GP which sound she is supposed to aim for. Rather than shivering, the GP or nurturer could also say the word for 'cold' aloud, if that is the chosen name of the sound in question. (In choosing the names of sounds, use words that the GP is already familiar with from earlier sessions.)
Can you see how this way of categorising and referring to sounds is more, well, friendly?
However, as a GP, don't try to exhaustively name every sound. Concentrate especially on sounds that you have great difficulty discriminating. Sound distinctions that you readily hear can gradually tune up your pronunciation. However, if you can't hear a sound contrast at all, then how will you know whether your own speech is conforming to host speech when it comes to that sound? You may learn to produce a contrast that you can hear, based on some articulatory instructions. However, if you can hear the contrast you are producing, but you can't hear the host contrast, then the contrast that you are producing is not the host contrast!
Starting late in Phase 1A, give a little attention each day to hearing host sound contrasts, using sound sorting, or listen and point with words that are almost identical.
For most people, their best attempts at describing the articulation of sounds ignores complex mechanisms of both hearing and articulating. An example would be the "explanation" that, "In aspirated stops, there is a puff of air following the release". Well, that is absolutely true, but it misses most of what is happening. If the vocal folds are closely approximated, then the airflow will be reduced, and will cause the vocal folds to vibrate. By contrast, if the vocal folds are far apart, then the airflow will be greater than when they are closely approximated. The longer the speaker waits for the vocal folds to come together (for example 20 milliseconds, 50 milliseconds), the larger the airflow will be. The waiting time before bringing the vocal folds together, even if the sound is said to be "unaspirated" or "aspirated" in articulatory phonetics, differs from language to language. Now even if you explain this complex mechanism (and there would be more to explain indeed), the GP doesn't have conscious control over actions like waiting 10 milliseconds and then drawing the vocal folds close together. So you'd be better off telling a GP, "it's a sound half way between a 'b' and a 'p'."
Furthermore, you'd only mention that if the person is majorly mispronouncing it. And then you wouldn't torture the person trying to get him or her to pronounce it perfectly before going on. We improve over time, and mainly because our hearing improves, and our pronunciation can then conform better to our improved hearing.
In Phase 1A, Session 1, Game 1, your hearing is vague and "blurry" (for people of most mother tongues hearing most host languages). You distinguish words based on salient features, such as "starts with 'pa...', or "has a strong 'mu' syllable in the middle somewhere". Quickly the "neighbourhood density" of words grows. There are now, two words which start with "pa..." or have a strong "mu" syllable in the middle somewhere. "Neighbourhood density" refers to the number of words that are similar to a given word. Once you know thousands of words, the neighbourhood density of many will be great, and you'll be forced to register a lot more detail than you did in Phase 1A, Session 1, Game 1! This is all part of the process of host pronunciation "coming clear".
After 30 silent hours in Phase 1, you start talking. Now your struggles to pronounce those familiar words will also move you to a new level in your listening for phonetic detail (and, we would claim, will have a much better impact on your listening than had you started talking in Phase 1A Session 1, Game 1).
Your own speech becomes clearer over the months as you interact intensively, and gradually, gradually, manage to make yourself more and more intelligible to host people through trying and trying. You are drawn to sound like the people you talk to.
With all this in mind, it just doesn't make sense to teach every GP a supposedly exhaustive description of every sound contrast using fancy latinate terms. Not a good use of time. It misleads them into thinking more is possible than is, fills their minds with "science" rather than filling their heart with nurturing, and it limits the amount of time that can be given to strategically learning to discriminate contrasts they truly have trouble with.
Therefore, GPs should especially concentrate on distinctions to which they are "deaf" or partially "deaf", and perhaps a few others that really seem egregious to the nurturer. But remember that which particular sound contrasts are difficult for a GP depends on the GP's mother tongue. So it would be wildly inefficient to have a detailed enough phonetics course for everyone regardless of mother tongue. Help with pronunciation needs to be personalised, and given with patience, and not overdone at any point in time. It is well known that GPs' pronunciation can be highly intelligible even though strongly accented. GPs will be strange to host people in so many ways, and pronunciation will be one of the more obvious ones. Teachers complain that phonetics lessons just don't seem to help a lot of people (perhaps citing particular nationalities) as though it is the people's fault. No, it is the teacher's fault for having an overly simplistic view of the challenges of developing host-like hearing and pronunciation.
Don't go overboard. Better to go underboard! Hearing and pronunciation keep improving for many months. If you intervene in trying to help a person to pay more attention to a sound contrast, intervene strategically, and be prepared to accept partial or total defeat. People with strong accents nevertheless become dear!