FRICATIVES

During the production of a fricative, the active and passive articulators are brought close together, but not near enough to totally block the oral cavity. This close approximation of the articulators means the air coming from the lungs has to squeeze through a narrow gap at high speed, creating turbulence, or local audible friction, which is heard as hissing for a voiceless fricative, and buzzing for a voiced one. English [f] five and [s] size are voiceless fricatives, while [v] five and [z] size are voiced.

The subclass of affricates consists of sounds which start as stops and end up as fricatives, they behave as single, complex sounds rather than sequences. Stops generally involve quick release of their complete articulatory closure; but if this release is slow, or delayed, the articulators will pass through a stage of close approximation appropriate for a fricative. The two relevant sounds for English are [tʃ], at the beginning and end of church, and its voiced equivalent [d], found at the beginning and end of judge. If you pronounce these words extremely slowly, you should be able to identify the stop and fricative phases.