What common condition relates to the absence of an ear canal?

The condition that relates to the absence of an ear canal is atresia. Atresia specifically refers to the congenital condition where there is an underdevelopment or complete absence of the ear canal, which can lead to conductive hearing loss as sound cannot travel through an occluded or non-existent passage.

Atresia can occur as part of a broader spectrum of ear malformations and often accompanies other ear anomalies. This condition can range from complete absence of the external ear canal to varying degrees of narrowing.

Understanding more about related conditions puts them in context: mastoiditis refers to an infection of the mastoid bone, which can occur in the presence of an ear canal but is not the absence of an ear canal itself. Microtia is a malformation of the external ear but does not specifically address the ear canal. Stenosis refers to the narrowing of the ear canal, which is a different condition from complete absence. Thus, atresia is the term that directly describes the condition of having no ear canal.