middle ear morphology trait tympanic membrane morphology trait Any measurable or observable characteristic related to the shape, structure, color or pattern of the thin, tense membrane forming the greater part of the lateral wall of the tympanic cavity and separating it from the external acoustic meatus; the tympanic membrane constitutes the boundary between the external and middle ear. Trait.ontology VT:0006018 drum membrane morphology trait membrana tympani morphology trait myringa morphology trait myrinx morphology trait