This thread, originally questioning the common status of auricle, attracted a lot of posts, but very few opinions about auricle. Even Jacki's original post was not entirely to the point, because she didn't say the word was unknown to her - merely that she didn't play it because she thought it wouldn't be classed as common.
Anyhow, I think the word should be treated as rare in future. It appears quite infrequently in published writings, and where it is used, it is almost always in a specialist publication. There are 89 instances of the word in COCA, the Corpus of Contemporary American English, but 80 of those are in academic journals. It is used much less often than ventricle, a word related to one of the meanings of auricle. So it will be rare in future.
