In the context of the first language of a speech community, the primary attention is paid to the analysis of its grammar and vocabulary by the linguists of that speech community.
Observation turned towards English pronunciation features when people of other speech communities started learning the language either for specific purposes (English as a foreign language: EFL) or for most purposes of everyday communication (English as a second language: ESL).
http://yementimes.com/article.shtml?i=902&p=education&a=2Kenneth