acousticon
/əˈkuːstɪk(ə)n/noun
Any of various devices used to assist hearing or amplify sound. Also figurative. Compare earlier otacousticon. Now rare.
Origin
Mid 17th century; earliest use found in Henry More (1614–1687), philosopher, poet, and theologian. From ancient Greek ἀκουστικόν, neuter singular (used in ancient Greek to denote the faculty of hearing) of ἀκουστικός.