Prosodic illusion refers to a perceptual phenomenon in poetry where the reader or listener experiences a rhythmic or metrical pattern that is not strictly present in the written or spoken form but is suggested through phonetic cues, syntactic phrasing, or contextual expectation. This illusion arises from the interplay between actual prosody (stress, pitch, duration) and the brain’s tendency to impose regularity on linguistic input, especially in verse that flirts with meter without fully conforming to it. For instance, a free verse line might "feel" iambic due to strategic placement of stressed syllables and caesuras, even though it lacks consistent metrical feet. Prosodic illusion is a key concept in cognitive poetics, revealing how readers actively construct rhythm through expectation and memory, and it underscores the dynamic relationship between formal structure and perceptual interpretation in poetic experience.

Prosodic illusion: A metrical effect that tricks the ear into hearing a regular rhythm despite irregularities; achieved through strategic stress placement or syntactic emphasis.