The rhaeadr effect in clinical phonology.

A distinction is drawn between Crystal's bucket theory of language processing and an overflow of effects between different linguistic levels in language production. Most of the examples are drawn from Welsh (a language of mutual interest to the author and the honoree of this issue). For that reason, it is proposed that this effect is termed the rhaeadr effect (from the Welsh for waterfall). The rhaeadr effect is illustrated with the initial consonant mutation systems of Welsh and Irish, and with data from both normal phonological (and morphophonological) development and disordered speech.