Cognate with Buryat шэбэнэхэ (šebenexe), see шивэр авир (šiver avir, “whisper”) for more possible cognates.
Probably formed with + -нах (-nax), a rare suffix used in onomatopoeic verbs.
шивнэх • (šivnex) (Mongolian spelling ᠰᠢᠪᠡᠨᠡᠬᠦ (sibenekü))