title: Feedback characteristics between implantable microphone and transducer in middle ear cavity.
abstract: With the advent of implantable hearing aids, implementation and acoustic sensing strategy of the implantable microphone becomes an important issue; among the many types of implantable microphone, placing the microphone in middle ear cavity (MEC) has advantages including simple operation and insensitive to skin touching or chewing motion. In this paper, an implantable microphone was implemented and researched feedback characteristic when both the implantable microphone and the transducer were placed in the MEC. Analytical and finite element analysis were conducted to design the microphone to have a natural frequency of 7 kHz and showed good characteristics of SNR and sensitivity. For the feedback test, simple analytical and finite element analysis were calculated and compared with in vitro experiments (n = 4). From the experiments, the open-loop gain and feedback factor were measured and the minimum gain margin measured as 14.3 dB.
authors.affiliation: Agency for Defense Development, Room 1009, 102 dong, Woo bang APT., Wall sung dong, dal sur gu, Dae gu 704-400, South Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Arman Woo
authors.forename: Seong Tak
authors.initials: ST
authors.lastname: Woo
authors.forename: Byung Seop
authors.initials: BS
authors.lastname: Song
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Cho
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D000818:Animals; D004432:Ear, Middle / Q000601:surgery*; D004867:Equipment Design / Q000295:instrumentation; D025461:Feedback, Physiological; D020342:Finite Element Analysis; D006168:Guinea Pigs; D006801:Humans; D019736:Prostheses and Implants; D014159:Transducers