The Development of a Biologically-Inspired Directional Microphone for Hearing Aids

Abstract

The development of novel microfabrication techniques for producing a directional microphone for hearing aids is here described. The mechanisms underlying both the structure and function of these unusual microphones were originally inspired by the ears of an inconspicuous insect, the parasitoid fly Ormia ochracea. The structure of Ormia’s ears inspired new approaches to design directional microphones that are more sensitive and have lower thermal noise than that typical of those using traditional approaches. The mechanisms for directional hearing in this animal are discussed along with the engineering design concepts that they have inspired, because they illustrate how basic research can inspire technology development–translational research. However, to realize the potential of bioexploitation this microphone diaphragm concept would have been very difficult to realize without the availability of new silicon microfabrication technologies. Thus, this report can be viewed as an example of what may be possible with the application of new fabrication methods to microphones. Challenges and opportunities provided by the use of silicon microfabrication technology for microphones are discussed.

A low-noise differential microphone inspired by the ears of the parasitoid fly Ormia ochracea

“…The microphone diaphragms again had dimensions of 1 ϫ 2 mm 2 and were fabricated out of polycrystalline silicon. These diaphragms have also been described in Miles et al ͑2004͒ andHoy ͑2006͒ and are predecessors of the design described in the present study. Saito et al ͑2002͒ reported a microphone diaphragm inspired by Ormia's ears that is supported on a gimbal.…”

A biomimetic coupled circuit based microphone array for sound source localization

“…12 The proportion of the two modes in the response could be used to determine the intensity difference response of the coupled circuit. We assume…”

Towards the development of a frequency agile MEMS acoustic sensor system

“…sound) in a limited time frame [1]. Designing acoustic sensors such as MEMS microphones, which are inspired by nature is not new [2][3][4]. Moreover, a novel acoustic bio-inspired concept was recently presented in [5] where the "transducer becomes part of the signal processing chain".…”