Affricate Consonant - Affricates Vs. Stop-fricative Sequences

Affricates Vs. Stop-fricative Sequences

Affricates can contrast phonemically with stop-fricative sequences. Examples:

Polish affricate /t͡ʂ/ in czysta 'clean (f.)' versus stop–fricative /tʂ/ in trzysta 'three hundred',

and

Klallam affricate /t͡s/ in k’ʷə́nc 'look at me' versus stop–fricative /ts/ in k’ʷə́nts 'he looks at it'.

In the stop-fricative sequence, the stop has a release burst before the fricative starts; but in the affricate, the fricative element is the release. Stop-fricative sequences may have a syllable boundary between the two segments, but not necessarily.

In English, /ts/ and /dz/ (nuts, nods) are considered phonemically stop-fricative sequences because they may contain a morpheme boundary (for example, nuts = nut + s). But the sounds are phonetically affricates. The English affricate phonemes /t͡ʃ/ and /d͡ʒ/ do not require a morpheme boundary. The sounds are sometimes written with the unitary symbols ‹č› and ‹ǰ›, though it is not considered standard IPA notation. However, English speakers (depending on dialect) do distinguish affricates from stop–fricative sequences:

• cat shit /kæt.ʃɪt/ →
• catch it /kæt͡ʃ.ɪt/ →

Here /t/ debuccalizes to a glottal stop before /ʃ/ in many dialects, making it phonetically distinct from /t͡ʃ/.

The acoustic difference between affricates and stop+fricative sequences is rate of amplitude increase of the frication noise, which is known as the rise time. Affricates have a short rise time to the peak frication amplitude while sequences of stop and fricative have relatively longer rise time (Howell & Rosen 1983, Johnson 2003, Mitani et al. 2006).