The automatic system is appealing in acquiring L2 pronunciation for several reasons. One is that the traditional method with a human teacher is highly labour-intensive and time/space-limited. Unfortunately, up to now there has been no effective way but to be taught by native teachers to achieve native-like pronunciation, also it the cost is prohibitive and sometimes learner's schedules make class attendance difficult.
A more positive reason is that it offers a powerful self-access facility. Learner-centered, self-pacing activities could easily be generated. i.e., ``The choice is up to the learners, so they decide where they want to study, when they want to study, and how long they want to study''. In particular, Hammerly (1982) found that adult learners find self-instructional programs advantageous, as they like the independence, preferring to be self-reliant rather than follow orders [8].
More importantly, a third reason is that it can prevent error fossilization. Traditional self-study materials such as a portable tape player and video cassette recorder (VCR) may well drive learners in the wrong way because they are often not conscious of their errors, and thus finally their incorrect pronunciation becomes fossilized. Finally, it can offer psychological stability to learners. Especially, shy, anxious learners who are often very uncomfortable in a traditional classroom as well as in a language lab where their privacy is not assured, could derive great benefit from the CAPL system.
