Impaired emotional prosody localises to the cingulate gyrus. Prosody denotes the musical contour of speech — pitch, rhythm, stress and tone — and its affective component lets us hear emotion in a voice. This affective layer is a limbic function, and the anterior cingulate gyrus is the central limbic hub that injects emotional and motivational drive into vocal output; damage here yields aprosodia, with speech that is monotonous and emotionally flat. The competing options serve different roles: the superior temporal gyrus underpins auditory comprehension (Wernicke's territory), the parietal lobe handles somatosensory integration, and the precentral gyrus is the primary motor strip for articulatory movements. None of these is the generator of emotional tone. Thus the cingulate gyrus is the lesion site producing loss of emotional prosody.\[\boxed{\text{Cingulate gyrus}}\]