Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
in-sŏno, ŭi, 1, v. n., to make a noise in or on, to sound, sound loudly, resound (mostly poet.): Boreae cum spiritus alto Insonat Aegaeo, roars on the Ægean Sea, Verg. A. 12, 366: insonuere cavernae, id. ib. 2, 53: caeli delapsa per auras Insonuit, resounded flying through the air, id. ib. 11, 596; cf. pennis, Ov. M. 13, 608: calamis, to play upon, id. ib. 11, 161: insonuitque flagello, cracked his whip, Verg. A. 5, 579; cf. poet. with acc.: verbera insonuit, id. ib. 7, 451: quasi faucibus aliquid obstiterit, insonare, to clear one’s throat, to hawk, Quint. 11, 3, 121.