Most human language travels first through the air. Speech is the vocal production of language through coordinated movements of the respiratory system, larynx, and articulators, yielding sequences of sounds that listeners interpret as linguistic units.

Speech differs from writing in permanence, processing constraints, and the presence of prosody and disfluency. It remains the primary modality of acquisition for spoken languages. Signed languages are full languages but are not speech; the term specifically denotes the vocal-auditory channel.

Speech science measures articulation and acoustics; speech pathology treats disorders of production and fluency. Technology for recognition and synthesis depends on detailed models of speech. Everyday interaction still relies on the speed and flexibility of spoken exchange.

• Vocal production of linguistic messages
• Uses respiration, phonation, and articulation
• Primary modality for spoken-language acquisition
• Studied in phonetics, pathology, and technology