Technique
Voice
Distinct from persona (a specific constructed speaker). 'Finding one's voice' is the central project of poetic development; each major poet's voice is immediately recognisable.
Definition
The distinctive personality, tone, and diction of a poem's speaker — the characteristic quality that makes a poet recognisable.
Example
Dickinson's voice: compressed, hymn-like, slant-rhymed; Whitman's: expansive, cataloguing, prophetic.