How long should a pronunciation activity last?

Pronunciation should never be the main point of a whole lesson. In general, pronunciation features that are important in producing a particular grammatical form or set of vocabulary items should be incorporated into a lesson which has that form or those items as its focus. So, for example, if you're teaching the past tense, you might want to include some pronunciation practice on final clusters with –t or –d.

How long should the activity last? In general, not more than 5 or 10 minutes at the most.

When should pronunciation practice come in a lesson?

There is no fixed rule about this. To some extent it depends on whether the focus on pronunciation is incidental – i.e. correcting a pronunciation error on the spot when it might lead to misunderstanding – or a planned activity which is in conjunction with focus on a linguistic form or a set of vocabulary.

For some kinds of pronunciation features, you may want to hold off practicing until you're sure that your students are having trouble with them. On the other hand, if you're teaching the past tense, you might want to start off with practice in pronouncing final clusters with –t or –d.

Pronunciation practice should probably come more frequently in courses where students are just beginning to study the language than in ones for more proficient students. At the beginning lever it is probably a good idea to systematically cover all features of pronunciation which are potential problems. However, again, this should not be done as the focus of any lesson. Each potential problem should be dealt with in connection with the introduction of meaningful units – words and grammatical structures – which contain this feature.

Pronunciation activities for more proficient students should nearly always be worked into a lesson with some other focus, such as teaching clusters with t- and d- in connection with s- or z- in connection with practising count and non-count nouns, singular and plural.

Teaching suprasegental features, such as the placement of sentence stress, can be done in connection with teaching selection and organisation of information in oral presentations. This would also probably be more appropriate for more advanced students. At a lower level, some introduction to suprasegmental features can be given in reading aloud. Here again, the focus would not be given in reading aloud. Here again, the focus would not be entirely on pronunciation. Pronunciation could be seen as a tool for expressing one's interpretation of a poem or passage.

（本文摘自：人民教育出版社2007年10月第版《语音教学入门》）