For the free passage of the sound into the ear, it is requisite that the tympanum be tense.
TENSE, n. tens. [L. tempus.] In grammar, time, or a particular form of a verb, or a combination of words, used to express the time of action, or of that which is affirmed; or tense is an inflection of verbs by which they are made to signify or distinguish the time of actions or events.
The primary simple tenses are three; those which express time past, present, and future; but these admit of modifications, which differ in different languages. The English language is rich in tenses, beyond any other language in Europe.