This document discusses phonetics as they relate to complete dentures. It begins with definitions of speech and phonetics. The history of considerations of phonetics in denture design is reviewed. The normal mechanisms of speech production are described, including the motor, vibrator, resonator, enunciators, and initiator components. Speech sounds are classified and various consonant groups are defined based on their place and manner of articulation. The document discusses the prosthodontic implications of different speech sounds and examines how denture design can affect speech. Tests for evaluating speech and potential speech defects are also mentioned.