scala vestibuli

noun

scala ves·​tib·​u·​li -ve-ˈstib-yə-ˌlī 

plural scalae vestibulorum -ve-ˌstib-yə-ˈlō-rəm 

: the lymph-filled spirally arranged canal in the bony canal of the cochlea that is separated from the cochlear duct below by the vestibular membrane, is connected with the oval window, and receives vibrations from the stapes