July 6: Types of natural sound change and their explanation in speech production, perception, and acquisition.

• Reduction and weakening processes: assimilation, neutralization. Tonogenesis.

• Strengthening processes: vowel and consonant shifts. The Great Vowel Shift in English. Chain shifts, mergers, and the issue of teleology. Dispersion theory. Evidence from ongoing change in English.

• Perception and acquisition as factors in sound change: dissimilation and metathesis.