operant vs vocal

operant

adj
  • That operates to produce an effect. 

noun
  • Any of a class of behaviors that produce consequences by operating (i.e., acting) upon the environment. 

  • An operative person or thing. 

vocal

adj
  • Uttered or modulated by the voice; expressed in words. 

  • Relating to, composed or arranged for, or sung by the human voice. 

  • Of, pertaining to, or resembling the human voice or speech. 

  • Consisting of, or characterized by, voice, or tone produced in the larynx, which may be modified, either by resonance, as in the case of the vowels, or by obstructive action, as in certain consonants, such as v, l, etc., or by both, as in the nasals m, n, ng. 

  • Used in the production of speech sounds. 

  • Synonym of expressive. 

  • Full of voices. 

  • Expressing opinions or feelings freely, loudly, or insistently. 

  • Having or exercising the power of producing voice, speech, or sound. 

  • Synonym of vocalic. 

noun
  • A part of a piece of music that is sung. 

  • A musical performance involving singing. 

  • A man in the Roman Catholic Church who has a right to vote in certain elections. 

  • A vocal sound; specifically, a purely vocal element of speech, unmodified except by resonance; a vowel or a diphthong; a tonic element; a tonic. 

How often have the words operant and vocal occurred in a corpus of books? (source: Google Ngram Viewer )