Lewis & Short

sŏnĭvĭus, a, um, adj. [sonus], noisy (cf. solistimum), only in the phrase sonivium tripudium, of the rattling of the corn upon the ground as it fell from the mouths of the sacred chickens, Cic. Fam. 6, 6, 7; Plin. 15, 22, 24, § 86; cf. Fest. pp. 290, 291, and 297 Müll.