I want to start from the most fundamental and hard problem to me (and maybe to everyone).
Two years ago, I had started a project to teach English to non-natives in English only.
Before lots of them had suffered from an ill-linked relationship between their native language and English. I had found this problem fairly early from my first start of learning foreign languages and help them to learn a more grounded meaning of each morpheme.
Now it turns out to be pretty effective to teach them more fundamental grounded meanings such as not just teach them 'prepare' but teach them meaning of pre- and pare so that these morphemes can work in other places too.
Now I faced another problem to teach the phonemes. I tried to teach them learn IPA symbols and to connect them with their sounds, but most of the people just dropped out in the middle of this course.
I need a simpler way of standardizing phonemes which is easily interpreted by the public to start with.
I want to listen to your advice and gather each one's intuition so that we could make a progress in teaching pronunciation and also developing a standardized way of speech recognition across different languages.