ABSTRACT
Universal Dyslalia means a disturbance of articulate speech which affects almost all sounds, thus rendering speech more or less unintelligible. Partial Dyslalia manifests itself in the disorder of one sound or one phonetic group, so that the communicative character of speech remains fairly untouched. It is striking that the vowel-sounds in Dyslalia are very little affected so far as the acoustic impression they convey is concerned. Closer investigation shows that this is due to the fact that the auditory deviation is below the threshold of acoustic discrimination for those hearing the dyslalic child. The character of Dyslalia suggests a comparison with the development and evolution of language in general, which might lead up to the explanation of the disorder. Dyslalia seems thus to correspond with dialect or, from a historic point of view, with an epoch or even several epochs in the development of languages.
