"to listen" (especially with a stethoscope), 1832, from Latin auscultatus, past participle of auscultare "to listen attentively to," from aus-, from auris "ear" (see ear (n.1)); "the rest is doubtful" [OED]. Tucker suggests the second element is akin to clinere "to lean, bend."
auscultate aus·cul·tate (ô'skəl-tāt') or aus·cult (ô'skəlt)
v. aus·cul·tat·ed or aus·cul·ted, aus·cul·tat·ing or aus·cul·ting, aus·cul·tates or aus·cults
To examine by auscultation.