The controversial connection between speech production and perception: theories vs. facts

Neurolinguistic investigations support the dissociation between speech production and speech perception in the case of aphasia. This means that an aphasic patient may be able to understand words and sentences while he is not able to produce them or, he may be able to produce certain linguistic forms properly while he is not able to detect the semantics of verbal utterances. Empirical data, however, seem to contradict the supposed excellent co-operation of speaking and perceiving in normal subjects as well. Various phenomena such as slips of the ear, violations of cooperation strategy of communication as well as the controversial connections of speech production and perception during language acquisition show dissociations of the two mechanisms. The question is how the properly working speech production co-occurs with inappropriate speech perception and what is the strategy where appropriate speech perception is escorted by inappropriate speech production.