speech

Speech is the vocal expression of language, produced by coordinated activity of the respiratory system, the larynx, and the articulatory organs. It enables the transmission of ideas, information, and emotion through audible sounds. Speech is a modality of communication and exists alongside other forms such as writing, sign language, and nonverbal cues.

Physiologically, speech begins with airflow from the lungs, regulated voicing by the vocal folds in the larynx, and shaping by the mouth and nasal cavities. The tongue, lips, jaw, and palate adjust to produce different sounds. The study of how sounds are made is phonetics, while how they are organized in a language is phonology. The production and perception of speech involve planning, encoding linguistic content, motor execution, and listening feedback, all of which can vary with context, emotion, and individual physiology.

Linguistically, speech comprises segments such as vowels and consonants, and their organization follows phonological rules. Prosody—intonation, stress, and rhythm—adds meaning and emphasis beyond segmental content. Variability arises from coarticulation, dialectal differences, and sociolinguistic factors such as formality and audience.

Development and disorders show the practical importance of speech. Children typically acquire articulation and intelligibility over several years. Speech sound disorders, apraxia of speech, and dysarthria involve articulation and motor control, while stuttering concerns fluency. Voice disorders affect phonation, altering pitch, loudness, or quality. Aphasia primarily affects language processing and may impact speech production.

In research and applied settings, speech is analyzed in linguistics, medicine, education, and technology, including speech recognition and synthesis. It remains a central aspect of human communication across cultures and contexts.