opening of external acoustic meatus

ex·ter·nal a·cous·tic pore

[TA]
the orifice of the external acoustic meatus in the tympanic portion of the temporal bone.

o·pen·ing of ex·ter·nal a·cous·tic me·a·tus

(ō'pĕn-ing eks-tĕr'năl ă-kūs'tik mē-ā'tŭs)
The orifice of the external acoustic meatus in the tympanic portion of the temporal bone.