Those working on the description of disordered speech are bound to be also involved with clinical phonology to some extent. This is because interpreting the speech signal is only the first step to an analysis. Describing the organization and function of a speech system is the next step. However, it is here that phonologists differ in their descriptions, as there are many current approaches in modern linguistics to undertaking phonological analyses of both normal and disordered speech.

Much of the work in theoretical phonology of the last fifty years or so is of little use in...