Design of a MEMS acoustical beamforming sensor microarray

This paper describes the design methodology for a microelectromechanical systems (MEMS)-based acoustical beamforming sensor microarray. The proposed acoustical array offers the potential of controlled directional sensitivity with constant beamwidth when used in conjunction with the appropriate digital signal processor. The array has been designed for use in a hearing instrument with a digital beamsteering engine to provide controlled directional sensitivity and constant beamwidth over the audio frequency range to improve speech intelligibility in noisy and reverberant environments. A MEMS-based packaging solution that allows the sensor array to be mounted in the ear canal is also described. The MEMS sensor-package interface features microspring contacts that enable low impedance connectivity between the sensor array and the related microelectronics. This allows the array to be easily removed for cleaning or replacement purposes.