otacousticon

From combining form of Ancient Greek οὖς (oûs, “ear”) + ἀκουστικόν (akoustikón), neuter of ἀκουστικός (akoustikós, “acoustic”).

• (UK) IPA^(key): /əʊtəˈkuːstɪkɒn/

otacousticon (plural otacousticons)

1. (now rare) An instrument to aid hearing, such as an ear trumpet or hearing aid.
   • 1621, Democritus Junior [pseudonym; Robert Burton], The Anatomy of Melancholy, Oxford: Printed by Iohn Lichfield and Iames Short, for Henry Cripps, OCLC 216894069; The Anatomy of Melancholy: […], 2nd corrected and augmented edition, Oxford: Printed by John Lichfield and James Short, for Henry Cripps, 1624, OCLC 54573970, (please specify |partition=1, 2, or 3):

     , New York Review of Books, 2001, p.69:

     […] Gyges' invisible ring, or some rare perspective glass, or otacousticon, which would so multiply species that a man might hear and see all at once […].