The Sound Pattern of English

The Sound Pattern of English (often known as 'SPE'), by Noam Chomsky and Morris Halle (1968), is the most significant work to date in generative phonology, the theory of generative linguistics as applied to phonology, the study of abstract units - based on aspects of articulatory movements - used to represent language. The book focuses on the phonology of English, showing how rules of phonology apply to underlying sequences of phonological units, leading to the phonetic forms uttered in human speech. Most subsequent phonological work in linguistics, especially in generativism, is defined relative to SPE, with most newer theories of generative phonology accepting the spirit of Chomsky and Halle's analysis if not the details.

Chomsky and Halle's work rejected the concept of the phoneme as a true unit of linguistic analysis; rather, abstract phonological features underlie what appears to be e.g. /t/ - the symbol in slanted brackets now merely a transcription convention. /t/ would actually stand for binary +/- features such as [-voice] and [+coronal]. These features together only roughly approximate to actual phonetic articulations - in these cases, lack of vocal fold vibration and the tongue making contact with the alveolar ridge. Features can be used to describe natural classes to which various processes may apply, representing patterns of phonological organization. /t/ is one of the units organised into several natural classes, such as a class where all members share [+coronal]: [j l ɹ n t d θ ð s z f v p b]. These units might be expected to share much phonological behavior as a result, such as susceptibility to similar sound changes over time or variant pronunciations.

SPE also saw the syllable as a feature rather than a unit of higher prosodic analysis. This view of the syllable largely did not survive subsequent research, but Chomsky and Halle's use of features continues, albeit often in highly modified forms.

Halle would continue to work in phonology and morphology, alongside other research interests. For Chomsky, however, this was his last significant work on phonology. His linguistic work would largely focus on syntax, producing the body of research for which today he is better known.