Cluster reduction is a phonological process where a consonant cluster (a sequence of two or more consonants, such as /st/, /pl/, or /skr/) is simplified by deleting one or more of the consonants. In effect, the child reduces the cluster to a single consonant – for example, saying “poon” for “spoon” or “top” for “stop,” omitting the /s/ in these blends. This simplification is a typical developmental strategy as young children acquire complex consonant sequences, and it often persists until about 4 years of age for most clusters and up to around 5 years for clusters involving /s/. Cluster reduction that continues beyond the expected age range is considered disordered; it can significantly affect a child’s intelligibility because many words will lose important consonant sounds, and intervention by an SLP may be needed to help the child produce all components of the cluster correctly.
Caroline Bowen, Children’s Speech Sound Disorders, 2nd ed. (Oxford: Wiley-Blackwell, 2015).
Paula Grunwell, Clinical Phonology, 2nd ed. (London: Croom Helm, 1987).
