The technical term for the voice cues that accompany spoken words, concerned with the sound of the voice and the range of meanings people convey through their voices rather than the words they use, is

The voice cues accompanying spoken words, tied to the sound and range of vocal meaning rather than the words, are para-language.

Pitch, tone, volume, tempo and pauses carry emotion and attitude as para-linguistic features.

Interpretation of gestures and body movement is kinesics, which reads the body rather than the voice.

The study of the sound units of speech is phonetics, a formal linguistic analysis rather than expressive vocal cues.

The informal rumour network in an organisation is the grapevine, unrelated to vocal delivery.

Para-language is why the same sentence can sound sincere, sarcastic or angry depending on the voice.