The pitch of the teacher's voice in the classroom is

The pitch of a teacher's voice is paralinguistic, belonging to the vocal features that accompany speech without being words.

Paralinguistic features include pitch, tone, volume, tempo and pauses, which colour how a message is delivered.

Linguistic refers to the words, grammar and structure of language itself, not to vocal quality.

Non-linguistic communication uses signs and cues outside voice, such as gestures, posture and facial expression.

Macro-linguistic is not a recognised communication category and does not describe voice pitch.

Paralanguage sits alongside kinesics, the study of body movement and gesture in communication.