active voice: the voice used to indicate that the grammatical subject of the verb is performing the action or causing the happening denoted by the verb
voice: (linguistics) the grammatical relation (active or passive) of the grammatical subject of a verb to the action that the verb denotes
paranasal sinus: any of the paired sinuses in the bones of the face adjacent to the nasal cavity that are lined with mucous membrane that is continuous with the lining of the nasal cavities