SCHOOL OF MECHANICAL ENGINEERING SEMINAR Wednesday, January 23, 2013 at 15:00 Wolfson Building of Mechanical Engineering, Room 206

Department of Mechanical Engineering, State University of New York, Binghamton, NY, USA

A difficulty in understanding speech in noisy environments is one of the most common complaints of hearing aid wearers. It is widely accepted that the use of directional microphone technology to eliminate unwanted sounds can improve a hearing aid user's ability to understand speech in noise. While directional microphones have been used in the audio industry for many decades, their incorporation into hearing aidsized consumer products poses significant technological challenges. By utilizing acoustic sensing principles we discovered while studying directionally-sensitive auditory systems in very small animals, new technologies are being created that overcome some of these challenges. A small, first-order directional MEMS microphone is described that is inspired by the ears of the fly, Ormia ochracea. This microphone has been shown to provide significant performance improvements over existing directional hearing aid microphone systems.

An extension of our first-order directional microphone design is described that can provide a secondorder directional output. This has the potential of providing unprecedented attenuation of unwanted sounds.

To achieve a significant reduction in the size of directional microphones, research will also be described on the mechanics of directional hearing in small animals that rely on detecting the acoustic particle velocity rather than sound pressure. It is hypothesized that microphones that respond to acoustic particle velocity could be made much smaller than pressure-based microphones.

Directional Microphone Technology for Hearing Aids

Prof. Ronald N. Miles